Gerrards Cross Computer Club

Backup Solutions - Cobian

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Page updated 5 September 2008

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What is this page for?

Backup is to protect us from loss of our important data. Loss can arise from hardware failure, e.g. the disk drive failing or some forms of computer crash, or our own failings when we have that Oh S**T!! moment when we delete an irreplaceable file or folder. It the latter case the recycle bin may be our salvation, but not always.

There are effectively three approaches to backup up computer data

  1. Head in Sand - do nothing
  2. Whole drive backup
  3. Selected file/folder backup

Note that any simple backup strategy will hold data for a limited period of time. If that time is exceeded then the data will be lost. If long term  recovery is envisaged then the backup strategy needs to be elaborated. this goes beyond the scope of this page.

Choice of File/Folder Backup Software

There are several candidate packages available. these include Syncback, Karen's Replicator and Cobian to name but a few.

When looking for backup software, and having tried several, I was looking for a solution that provided the following features

Feature Wish List Cobian's Support for Feature

Ability to backup data automatically on a schedule without intervention.

Cobian  supports multiple jobs that can each be scheduled

Ability to backup without significant impact on the computer that is being backed up. Cobian behaves in a friendly way. It can be configured to run at a lower priority than normal programs and hence is almost totally transparent in its use.

Ability to backup files, such as Outlook Express, without shutting down those programs.

Cobian can us Volume  shadow copying enabling it to backup files that are in use

Ability to optimise disk usage

Cobian supports backup cycles. See below for more details

Ability to restore computer data to an earlier state

This is the area where Cobian is weakest. It has no facility for automatic restoration. Windows Explorer can be used to copy the files manually

Ability to select what is backed up. this involves both inclusion of items and selective exclusion

Cobian has support for inclusion and exclusion of explicitly specified files or folders or wild cards

Ability to backup:

  • "My documents" for multiple users on a single machine
  • "Documents and Settings" for multiple users, including All Users on a single machine.
  • Outlook Express files
  • Windows Address book
  • Registry

Cobian can be configured to run using an administration account so that it has permission to copy any user's data

The registry copy is not directly supported but Cobian has the facility to run a program prior to the backup starting enabling third party tools to be executed. ERUNT is a registry backup program that can be run from a command line that can readily be integrated into Cobian's backup schedule.

I was unable to find any other programs that came close to meeting these requirements and were free. Syncback Pro probably comes closest but is not freeware.

Backup Cycle

When choosing a backup strategy one important factor to consider is how much data to backup and how often. This must also be balanced against how long the backup takes and how much storage it requires.icy-spindown-fix.html

Storage requirements can be optimised using data compression. Cobian supports this but I have chosen not to use it. I am content with other optimisation methods described below.

There are three principle ways of backing up a set of files using Cobian:

Type Backup Comments Restoration Notes Comparison
Full Backup All files in the set are backed up each time a backup is run Restoration is easy in that all the most recent files are always available in a single folder Increased size of backup set compared with differential and incremental

This is used in conjunction with a full backup

All files that have changed since the last full backup are backed up

Restoration is relatively easy in that you need to restore the last full backup and then the most recent differential backup Size is reduced from a full backup but backup time and size required increases with each successive backup

This is also used in conjunction with a full backup

All files that have changed since the last backup (whether full or incremental) are backed up each time the backup is run

Restoration needs care to ensure that all the files are recovered. You may need to apply all incremental backups successively from the full backup.The functionality tab also has some options that you may want to experiment with. Smallest amount of disk space used. 


The trade-off between storage used and time take and easy of recovery is a personal decision. It is also necessary to think about the reasons for backing up data in the first place. We back data up so that we do not lose it. Loss however can occur from hardware failure but can also arise from human frailty. How often do you have an oh s**t moment when you have deleted a vital file. 

For pure disk recovery it may only be necessary to keep yesterdays full backup. To protect against accidental deletion may need to keep files going back indefinitely.

Each of us has to make our own decision and here is my current strategy.

I backup the following file sets

The rationale is that different types of data may need a different backup strategy. The address book for example is important and entries can all too easily be deleted from it accidentally. there is only one file and each time it changes it will be recorded if incremental backups are taken. There is therefore no need to ever take a full backup as this will just waste space. Email is similar in that each folder (at least with Outlook Express) contains many emails. By default all of these are contained within documents and Settings. Most of the other entries within Documents and Settings are far less important.

I use a full backup weekly with a daily incremental backup.

I keep four full sets. This allows me to go back one month.

Disk organisation

I have structured my disk as follows, this is to simplify backing up the data

I also take a full drive backup of by C drive and U drive periodically (interval still to be determined). I am also currently taking a backup of my S drive but intend to discontinue this.

The following installation and configuration instructions are based on this configuration.

Download Location

Here is the link to Cobian home page - select software and then backup.  The version we are using is Cobian 9.


Installation follows normal windows practice. Double click on downloaded file. Click on screenshot to show a full resolution image (resize window if necessary).

Installation Instructions Screenshot

Install by double clicking on the downloaded executable install file. The first choice is to choose a language.

The default is English but perhaps you have reason to select an alternative! the rest of this page assumes English!

Click OK to continue

Choose your language

We are now presented with a license agreement - read every last full stop and comma ;-) as one always does!

Click on the checkbox to accept the agreement and click Next to continue.

License page

The default installation location is normally acceptable.

Click on Next to continue.

Install location

The next screen requires some explanation. For fully automated operation it needs to be installed as a service. This means that part of the program is always there waiting to be run. The user interface interacts with this resident component. This option is the default.

We must also choose the account name that must be used to run the program. enter the user name and password. Note that it can easily be changed later. More details below.

Set credentials

Here is the final screen. If an error was detected e.g. the user account credentials were incorrect then the installation would fail and the error message would be visible.

Clock on Done to complete the process.

Cobian is now running on your system and a nice toadstool icon should have appeared in your tray at the bottom of your screen.

Skip forward to the configuration section

Installation complete

User Credentials

Cobian should be installed as a service so that it is always there and ready to run whenever the computer is switched on. You do NOT need to be logged in for the backup to take place. When Cobian runs backup jobs it needs to have read access the files that need to be backed up. It must also have write access to the storage device. This means it must run with user account credentials that git it access to all the necessary files.

Windows file permissions are not too difficult to understand. Briefly however it is normally sufficient to configure Cobian to run as an administrator to be able to access local files. 

Note that if you are backing up across a network  blank passwords are not normally acceptable. It is also important that Cobian has permission to create folders and write files on the networked computer. This usually requires that a matching account (username and password) is created on the networked device.

My solution to this account issue is to create an account with administrator privileges specifically for Cobian. With windows this would normally then appear on the initial Welcome screen but this can be hidden see below.

A further constraint, if you are using a networked NAS device or a network connection to another computer, is that it may not support user names containing space characters. Mine did [John (Administrator] and I had to create new accounts to get round this issue.

If you need to create a new account follow the steps below:

Account Creation Screenshot

Create an account through Control Panel /The functionality tab also has some options that you may want to experiment with. User Accounts

Click on Create a new account

Create account

Enter your chose account name. Here for demonstration purposes backup has been used. You must choose your own.

Click Next to continue

Create Account

Ensure that computer administrator is selected and click Create Account.

Creat admin account

We now must define an account paScreenshotssword.

Click on the icon associated with the newly created account.

select account

We now need to set a password on the account so that backup can take place to a networked device.

Click Create a password

Notes on delete empty folders

set password

We must now enter a password and repeat it (to ensure that you have typed it correctly).

You can enter a reminder hint if necessary. If you do not intend to use the account for anything other than backup then a hint is probably not necessary.

Enter password

A new account has now been created and will appear on the Welcome screen when you boot up. This can be hidden as follows.

Hiding User Accounts

Instructions Screenshot

Download the VBS Hide user file :- go to Doug Knox's site

Click the download link indicated to download the .vbs file and save it to the desktop or anywhere else that is convenient.

Note that you could also download the unhide script if you ever want to revers the process.

Hide user download page

A security warning will appear asking if you want to open this file - of course you do!

Type in the user name e.g. backup you chose and click OK.

The username should no longer appear on the Welcome screen.

hide user

Configuring the Program - Initial

Click on the Desktop icon or use the Start/run menu to start the program.

Starting program

Runtime Instructions Screenshot

This is the Cobian icon in the system tray (bottom right hand corner of your screen).

Double Clicking on the icon opens the Cobian management application. You can also Right Click and select Open from the menu

Tray Icon

This is where we start from. The left pane will show backup jobs that have been created. the right hand pane is a tabbed display that can show the log associated with the current job (as seen here) - it is showing the initial state of the application as it has not yet been run. This will be called the log window in the following description.

The browser tab takes you to the Cobian Home Page

We will look at the other tabs later.

There are also icons along the top - hovering the mouse over these shows their purpose. The functions can also be accessed through the menus.

For now we will select the menu Tools / Options or (click the spanner icon).

Managment screen

General Tab

Runtime Instructions Screenshot

This now brings up the configuration dialog. The left pane contains various configuration options and we will look at the essential parts of these later. The initial selection is General.

On this screen note that it is set to autostart for all users. this means that any user can see, and change, settings. you make wish to allow only certain users to make the changes. this does not affect the automatic backup schedule - just access to the user interface.

Note also the Logon button. This allows you to change the Logon credentials that were supplied during installation.

The Stop and Uninstall buttons refer to the service that is always running. You should not need to change these settings.

The language selection should be self explanatory.

The Hotkey is yet another way of bringing up the user interface.

The Temporary directory is where Cobian will create any temporary files. Write access is required to this folder from the account being used to run Cobian, not necessarily the account you are logged in as.

Automatically check for updates is self explanatory. This will show as a message in the log window.

The Update Proxy button is unlikely to be needed by home users. It is used when you are behind a firewall with a proxy server. If you have not configured a proxy into Internet Explorer then you don't need to use this button.

The checkbox Backup everything on start, if set, will run all backup jobs when the program is first started

Click on OK when you have finished configuration. It appears on all configuration screens.

General configuration screen

Options not described on detail

There are several selections on the left hand pane that we will not be looking at in detail

Log Options

Runtime Instructions Screenshot

The next configuration page we examine is the log options. This affects what level of detail is shown on the log window when the program is started and when it is running.

The options shown here are the default values and I have had no reason to change them.

The Mail log file checkbox will enable the next configuration option SNMP. This is unlikely to be of interest to us for this type of backup and is not shown here. 

Logging options

Engine Options

Runtime Instructions Screenshot

These are the Engine options. The screenshot shows the default options.There are a number of options here that are worthy of note.

Calculate the progress exactly. This slows down the backup. Your choice.The functionality tab also has some options that you may want to experiment with.

Force first backup to be full. This is an important option and should be selected. If you have chosen Incremental or differential backup you want a full backup to start of the process. This ensures that this will indeed be the case.

Low priority for the working thread. Selecting this means that your use of the computer will take priority over the backup. the backup may run slower but you will be largely unaware of it taking place. Your choice but recommended.

Copy file attributes - you want this

Check CRC for file copy operations - this option will check the file copy by computing a checksum on the copied file and comparing this with the original file. It significantly increases the time for a copy and has been found to fail spuriously.

Copy file timestamp - you want this as well

Copy NTFS permissions - This is a good idea.

Park the first full backup - This will ensure that the first full backup will never be automatically deleted. Although this is the default I have chosen not to use it.

Delete empty folders - I have chosen to use this option. Any folder that does not contain data is removed. Otherwise an empty folder structure is retained. See below for comments on this option.

Always create directories - If this is not selected I believe that all files go into a single folder - I will try some more tests to confirm.

Apply masks to subdirectories - I don't see why this option should not be selected.

Copy directly if VSS Fails - this will attempt the backup if Volume Shadowing fails - again why not allow it to try.

Engine options

Configuring Backup Jobs

This is where we really get to grip with what the program is for. Backup up our computer!

We will look at some of the options available. You may have different requirements but the approach below should enable you to tailor the backup jobs to suit your own circumstances.

Configuration Step Screenshot

This screenshot shows an empty task list - we must now populate it. We will start with Admin's Documents&Settings by way of example

Start by Right Click anywhere in the Left Hand pane. A pop up list will appear.

Click on New Task. Alternatively use the Task Menu and select New Task.

Empty job/task list

General Options

The initial display shows the General options. You can always return here by selecting it again.

The screenshot shows the initial state of this window. Configuration steps are shown in the Left pane and details to be entered on the RH pane. Any of the options can be changed at any time. The OK and Cancel buttons will appear on all configuration pages - ignore them until you have configured everything. the second screenshot shows a typical set of parameters.

Configuration Step Screenshot

The Task Name will appear on the list of tasks. You should give it a name that makes it easy to identify e.g.
Admin Docs+Settings

Note that this will be the root of the folder name. some storage devices (based on UNIX) do not like & characters so  plus is suggested rather than &.

Disabled Checkbox makes it possible to create a task that does not run. This might be useful for a job you only want to run occasionally.

Include subdirectories will backup a folder and all folders contained within it.

Create separate backups  will always create a new folder or file with the data appended. If not selected the backup will be overwritten. Recommend keeping the default setting.

Use file attribute logic - see below

Clear the archive bit - see below

Use Volume shadow Copy - enables backup of files that are open e.g. Outlook Express. Only works to XP and Vista when using NTFS.

Backup type and Full copies to keep control the backup strategy adopted and are described below

Initial form:

Initial file settings

Completed form:

Completed form

Detailed descriptions of some General options

Create separated backups using timestamps

When Cobian runs it will use a destination folder that we will specify on another configuration page. When it starts this task It will create a sub folder based on the task name and the current date and time. this makes it easy to find a file-set by date.

Use file attribute logic and Clear the archive bit

Windows file systems have a flag or attribute associated with every file. This flag is set every time the file is written to. This was invented to assist backup programs to identify files that have been changed since the last backup. This of course only works if the backup program clears this flag when they have backed up the file. The Clear archive bitClear archive bit option does just that.

There are some circumstances where this facility does not work. One situation arises if you are backing up a Linux/UNIX file store across the network. In this case you would probably want to change the default settings. 

Backup type and full copies to keep

There are three (or even four) types of backup.

  1. Full Backup - This will always copy all your files from the source to the destination.
  2. Differential Backup - this will copy all files that have changed since the last full backup. the size of this backup will increase with time as more files are changed.
  3. Incremental Backup - This will copy only those files that have changed since the last backup (whether Full or Incremental)
  4. [Dummy - This is not a backup! It is provided to allow scheduled non backup jobs to be scheduled. See the help file.]

If you have been reading this carefully you may be wondering how an Incremental backup can have a full backup associated with it. Cobian is clever. It will always make the first backup a full backup when you select Differential or Incremental.

You have further options

  1. Full copies to keep - In conjunction with the next option, this will control how many full backups will be kept. When the number has been reached then older full backups and all incremental and differential backups that depend on these oder full backups will be deleted from the destination.
  2. Make a full backup every - This will control how many Incremental or Differential backups will be made before another full backup is made. If a value of 6 is entered then there will be six incremental backups before a full backup. This means a full backup will be taken once a week (assuming that the computer is used every day).

In should be noted that if the general option to delete empty folders is selected then although Cobian will check all the files and report that the backup has been complete, and will show an entry in it's history window, no folders will remain on the destination. See below for more information

Files Tab

This tab will select the folders and/or files that will be included in the backup task. Several folders or files can be selected as the source. 

Several folders can be selected as the destination in which case the files will be copied to ALL destinations.

Configuration Step Screenshot

We now select the folder or folders that will be backed up.

In this example we have selected the documents and Settings folder for the user admin. The screenshots show before and after.

We have selected a target folder on a networked drive but it could be a network drive mapped to a drive letter. It could also be a local drive in the same computer or a USB drive. If it can be accessed you can use it!

we have only selected one source and one destination.

Initial form:

Files form - initial

Completed Form:

completed files

Schedule Tab

We now set the schedule to cause the backup to run at regular intervals.

Configuration Step Screenshot

There are a number of options that can be chosen. the default is daily which is what I use. If you select weekly then you can also select the day of the week. Explore the options - they are all quite obvious.

for the daily option if is necessary to set a tie that will be used each day. this defaults to the current time. I like a nice round number and set my three computers to backup during the evening, 30 minutes apart.

Initial form:

Initial schedule screen

Completed Form:

Completed schedule

Archive Tab

This allows you to zip the archive copies. I have not used this option and have therefore not shown the configuration details.

Special Tab

This is where we can chose whether to include or exclude files from within the folders selected in the files tab. You will not always need to use this tab but it can be useful with the documents and settings folder to apply different backup strategies to selected areas of the source folder.

An example of this is to EXCLUDE all Outlook Express email from the standard backup nd then to backup OE email separately. This is part of my own strategy. I also exclude the Address book and back this up separately as well. 

Configuration Step Screenshot

To add files to the INCLUDE list click on the appropriate Add button. You can add files, folders, or a mask.

A mask is otherwise known as a wild card e.g. *.jpg will include all files with a file extension of jpg. For this example we do not need to add any files.

It is similar for the EXCLUDE files. To exclude Outlook Express files you need to know where to find them. 

The path is long and it does not all show on the screen shot. I suggest you browse to it using the Directory option.

C:\Documents and Settings The folder we are backing up
\admin The user we are backing up
\Local Settings Just follow the path
\Application Data and again
\Identities and again
\{..................} A long and complex identity
Microsoft at last!!
Outlook Express The folder

Once you have selected the folder you will find that the wildcard *.* is automatically added.

You can add the address book in a similar way. This is found in

C:\Documents and Settings The folder we are backing up
\admin The user we are backing up
\Application Data This is where it differs from OE
\Microsoft The are in this branch as well
\Address Book The address book folder

If you use Firefox then you will have to look for the equivalent folders yourself - sorry! the principle should work however.

Initial form:

Special tab

Completed form:

Completed special

Note that there is a significant amount of data in Documents and Settings that almost certainly does not need to be regularly backed up. To be certain however takes considerable research and I am still investigating. Remember that it is better to back up more than you need rather then missing a vital file because you were mistaken.

Events Tab

This tab is used when you need to run a program (or more) before taking a backup. this can be used for taking a backup of that dreaded Windows Registry!

There is a program called ERUNT. Download instructions are below. This has "command line2 parameters that control what it does. These are described in a file which accompanies the program.

The parameters shown in the example will backup the current system, user, other users registry hives (that is what the individual parts of the Registry are called).

It is assumed that the registry backup will take place to C:\Windows\ERDNT. This folder does not need to exist but it might be more convenient for setting up the source folder for the backup if it does. Create it manually.

Create a backup task to backup C:\Windows\ERDNT to your chosen backup device.

Configuration Step Screenshot

Click on Add, select Execute and Wait and browse to the folder where ERUNT is installed and click on the file ERUNT.EXE.

A new dialog box will open where additional parameters can be entered.

Enter the following (copy and paste), the parameters are explained below.

C:\Windows\ERDNT sysreg curuser otherusers /noconfirmdelete /noprogresswindow

A warning will appear that if the called program does nt terminate then the backup will never finish. We must however wait until it finishes so we can thank the Cobian author for his concern but we can click on OK and continue.

Registry backup will take a while to complete. When this finishes however, if you have correctly set up a backup task to copy the folder to the archive device your registry will be safely backed up.

Note that restoring the registry requires the use of a different program ERDNT. ERUNT kindly places this executable file with the backup of the Registry.

Initial form:
Event tab
Completed form:
Completed Event

Download and configure ERUNT

ERUNT can be down loaded from

The parameters used in the Event window are as follows:

Parameter Description
C:\Windows\ERDNT This is the folder where the backup will be stored. It does not need to exist and will be created as required

System registry: The current system registry, usually consisting of the files DEFAULT, SAM, SECURITY, SOFTWARE, and SYSTEM


Current user registry: The registry files for the currently logged-on user, usually NTUSER.DAT and USRCLASS.DAT

Other open user registries: Sometimes Windows has a few other user registries in memory. Examples for this are "generic" registries, e.g. for user "EVERYONE", or registries of other users if you use Fast Task Switching in Windows XP. Check this option to backup all these additional user registries (if found) as well.

This will delete any existing files without prompting the user - essential for unattended backup


This suppresses the backup progress window. This could be intrusive if it popped up while you were working.

We have configured it - What happens now?

We have configured Cobian to backup out system - how does it behave?

Cobian will normally sit quietly in the background minding its own business waiting for the time you have defined to come round. You can always wake up the user interface by double clicking or Right clicking on the toadstool icon in the system tray.

Description Description

When you start the program now you will see a list of tasks in the left hand pane. It will normally select the Properties Tab on the Right Hand pane as shown here.

You are able to select one or more tasks by clicking on a task to select a single item. By holding down the CTRL key and clicking on several tasks you can select more than one.

Runtime task page

When you select a single task it shown a summary of the properties of that task. It auto

Note that double click on most properties takes you to the screen where these can be changed.

Selected tasks may be run manually by clicking on the icon above this pane containing a single floppy disk image (hover the mouse to confirm).

All tasks can be run by clicking the icon to the left showing two floppy disks.

Taks properties

With a single task selected you may look at the history of the backups. When you first start this will be empty. when the program has been running for a time it will show a series of Full backups followed by a set of Incremental backups. 

The screenshot shows my desktop computer with three full backups (the number I have asked it to keep) and six incremental backups in between apart from the last. 

The cycle is not complete in this example. It adds one of these each day.

when the configured maximum number of Incremental backups has been completed Cobian will make the next backup into a full backup.

If the maximum number of backups has been exceeded it will delete older full backups and all dependent Incremental backups. However see delete problem described below.

Runtime history

When a task is running a log is created. the pane, by default, only shows the current job. In this case one file was backed up.

Note that when automatically backing up the log is still created and can bee seen if the user interface window is opened. 

I tend to only look at it if I am testing a new configuration. i leave Cobian to continue to do its job.

Example log

Notes on delete empty folders

Empty folders arise when using incremental backup and no files have changed within that folder. This will happen frequently if the number of documents changed per day are few.

Selecting to option to delete empty folders removes all empty folders, The benefit of this is that it is easier to determine when a file was last changed. The deletion goes as far as the root folder which is also deleted. This is OK but Cobain appears to retain an entry on it's own records.  When it comes to delete these folders it does not always remove entries where the folder that should be deleted does not exist. They can be deleted manually.

Note that this fault is not totally repeatable