How to Backup the Windows Registry



In simple terms the Windows Registry can be thought of as a file containing an extended inventory of all your PCs hardware and software.

When Windows starts up it consults the Registry in order to know how to relate to your specific hardware and software.

It's a file that's essential to Windows. If it gets corrupted Windows won't be able to function properly.

And it does get corrupted; rather too often actually. That's why it's good practice to have a backup copy.

Easy, you say, I'll just copy the file to another location.

In Windows 95, 98 you can do just this. The Registry consists of two files system.dat and user.dat located in the Windows folder and you can simply copy these to another folder to create your registry backup. ME adds a third file, classes.dat, but it too can be simply copied.

This simple approach won't work with Windows NT and later versions as the Registry files are locked by the system and can't be easily copied.

Windows addresses this by providing automatic backup of the Registry as part of the automatic System Restore feature. This feature is enabled by default when Windows is installed.

If you have left the System Restore feature enabled on your PC then your Registry is automatically being backed up. If it gets corrupted Windows will automatically try to recover it from previous restore points.

However, many users, me included, turn the System Restore feature off as it is a notorious disk space hog. Once turned off, your Registry is no longer being backed up.

Thankfully, there are a number of utilities that will back up your Registry. One of the best is also free. It called ERUNT.

ERUNT (Emergency Recovery Utility for NT) will backup the Registry for all Windows systems from NT onwards. It also allows you to recover from backup either through a special recovery program or through the Windows Recovery Console.

And it's fast, very fast.

With ERUNT it's also possible to set up automatic Registry backups using the Windows Scheduler.

As a bonus, ERUNT includes another utility NTREGOPT that allows you to defragment your Registry. To be frank, I've never myself seen any performance improvement from registry defragging but then again it does no harm either.

ERUNT is easy to use but it's not intended for raw beginners. Raw beginners will most likely have System Restore enabled anyway so they won't need to back up their Registry.

Freeware, Windows 95 and later, 773KB



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In reference to johnvk's comments last month regarding's Registry Backup. I've been using it for about 6-months. With very few exceptions, the backup works perfectly. The rare problems have to do with Volume Shadow Copy not working correctly. When that happens, I do get a backup of my account, however, other user accounts are excluded. I've seen one consistent possible problem that I've reported to Shane sometime back and that has to do with Windows Reliability Monitor showing an application error that the program "stopped working". This occurs every day, even though the registry backup and log files are fine. As yet the problem has not been addressed. Check to see if this is a problem on your system as well. I'm running Windows 8 Pro x64. -SA Jack

ERUNT vs Registry Backup?

ERUNT sounds great because it backups up the actual FILES rather than the "contents" and so if your system doesnt boot (and thus many other backup/restore methods are unavailable) you can use the venerable COPY dos command to restore. Or ERUNT.exe can do it for you.

But (who's "Windows Repair (All In One)" is recommended on this site and i've used it twice with splended success) also has a Registry Backup.

It talks about 2 possible problems with ERUNT

1. not backing up other users, just the current one.
2. perhaps invalidating other programs' handles (presumably to the registry)

Quoting that page:

A lot of registry backup programs use the RegSaveKey API, such as ERUNT. When using the API you can only backup loaded registry files. [Only the current user's registry NTUSER.DAT file is loaded, and so only it is backed up.] - Registry Backup uses the volume shadow copy service instead. This allows perfect backups of the registry files and all profiles on the system.


Quote From Microsoft:
"Applications that back up or restore system state including system files and registry hives should use the Volume Shadow Copy Service instead of the registry functions."

"Using RegSaveKey together with RegRestoreKey to copy subtrees in the registry is not recommended. This method does not trigger notifications and can invalidate handles used by other applications."

By using the Volume Shadow Copy instead of the RegSaveKey API this registry backup program is safer to use.

End quote.

Have people used Registry Backup and found it reliable, as they have ERUNT? Is it really safer than ERUNT, as its author claims? I'm not sure i *want* to trigger those notifications when i'm backing up the registry. That's nobody's business, right? But what about that "invalidate handles used by other applications"? I can see that might be a problem when *restoring* using RegRestoreKey--maybe that doesnt trigger the handle. But on save? Who needs to see that? Or is Micro$oft just trying to make sure *their* digital eyes see everything. So i would like opinions on this.

And the backing up of other users is valid, ERUNT even says so.; What do people think of that?

(Also there is a comment on this page that appears to be spam with pseudo-legitimate text (probably to avoid auto-spam-detection): "Anonymous on 18. March 2009 - 0:12 (18073)")

Beware of the scam "free scan for hidden Windows errors" link at the top of the page containing their registry backup which points to a site with a deserved poor WOT (Web Of Trust) rating. Ethically compliant sites should not carry this rogue garbage just to make money. MC - Site Manager.