If you're getting error messages that point to some kind of problem with your Windows registry, you should take action before things get worse.
Lets take a look at different ways to fix your Windows registry.
Restore the Registry from a Custom Backup Let's face it: most people don't backup their computers.
And of those who actually do, backups may be several months old or they don't work.
But for the sake of illustrating this option of fixing the Windows registry, let's assume for a moment that you belong to that exclusive group of people who actually have a recent and working backup of their system.
The Windows registry consists of two files: system.
dat and user.
dat, which are located in C:\Windows (or whatever your Windows installation directory is named).
You can't restore these files into a running system because they are locked, so you will need to boot Windows either from a boot CD (such as the Windows installation CD) or from the network.
After you've booted Windows from a medium other than the installation you want to fix, simply overwrite the files user.
dat and system.
dat with the versions that you backed up earlier.
You will need to remove the hidden and system attributes of both files before you can do that.
And be sure to restore those attriburtes after restoring, so they can't get deleted accidentally.
Restore the Registry from a System Restore Point The second option for restoring the registry database are so-called system restore points.
Windows (XP and Vista) automatically creates these restore points whenever significant changes, such as installing software, are made to the system.
This makes it easy to "go back in time" in case of a system error, to a point where everything was still working.
Restore points are basically "snapshots" of your Windows system at a certain point in time.
Restore points can also be created manually, but as with manual (custom) backups, users rarely make use of this feature.
This means that you can only revert back to a restore point Windows has made automatically.
This is better than nothing, but if the last restore point is several weeks old, you will lose any changes made to your system during that time.
Fix the Registry with a Registry Repair Tool If you've failed to either create a custom backup of your system or a restore point with the on-board System Restore utility, you still have the option of repairing the registry.
You will need a registry repair tool for this, of which several are available.
The way these tools work is that they first scan the registry for inconsistencies and then allow you to repair these errors automatically.
Most tools, the better ones, allow you to choose which errors you actually want to repair and, just in case, they backup your current registry so you can revert back to the previous state in case anything goes wrong.
There are numerous registry cleaners on the market, and how good they are at their job varies greatly.
The most important thing to look for is whether a tool allows you to make backups and of course how good a job it does at detecting and repairing registry errors without removing anything that's supposed to be there.