Windows' Restore Point feature backs up and restores the Registry. To get to it in XP, open the Start menu, head for Help and Support, and choose "Undo changes to your computer with System Restore." Choose "Create a restore point" to back up your Registry; to restore the Registry, select "Restore my computer to an earlier time." (You can also get to the tool from Start, All Programs, Accessories, System Tools, System Restore.)
If you're stuck with Vista, read the tutorial at bleepingcomputer.com.
The system restore controversy
I have lots of smart readers and they often chime in when I write about something technical. Here some comments from my blog.
"Two out of three times I have used System Restore every restore point is corrupt. The third time, I restored successfully, but my problem wasn't fixed, so I undid the restore. Well, that turned out to be a huge mistake. It screwed up Windows so bad, I had to use my recovery CD!" — Darkmonk
"Sometimes the System Restore points get corrupted. I get a [Windows] error message that says 'System Restore was not successful, Please try a different restore point. Nothing was changed on your system.' I get this message until I turn off System Restore, and then turn it back on again. You would think Microsoft would fix it in Vista, but the problem still is here." — poweruser2
"My experience tells me that ... if you have installed third-party backup software, Microsoft's System Restore will fail. Or, if you have downloaded a virus that embeds itself into the restore point, your antivirus software may be preventing the restore from working." — antb
"I recommend using a drive image of a clean install of the OS and all the primary programs... I also use Carbonite[http://carbonite.com/] online [a fee-based service] in addition to backups to another drive. That way if the entire system is wiped out by a fire or theft, I can at least get my images and documents back." — digitalzen
Trouble with System Restore?
If you ever have trouble with Restore Points, read . (You might want to print it out and put it somewhere safe, just in case.) Also, Bert Kinney has an immensely valuable System Restore FAQ which includes details about corrupt Restore Points.
Some of you may be in a geeky frame of mind, so try Scott Dunn's Create instant restore points trick, which uses a small script, or download Doug Knox's Single click creation of a system restore point/runs as a scheduled task.
Finally, blog reader bobwool recommended ERUNT (Emergency Recovery Utility NT) as "a great freeware tool that backs up your registry and allows you to restore it." He's absolutely on target; Lars Hederer's ERUNT is a handy, donation-supported utility to have in your toolbox.
Removing restore points
There are a couple ways to get rid of Restore Points.
The first uses the Disk Cleanup utility to remove all but the last Restore Point. From My Computer, right-click the C: drive, choose Properties, and click Disk Cleanup. Once the hard drive stops churning, you'll see a list of items to delete, such as Temp files and the Internet cache. You might as well dump those, too. Next, choose the More Options tab and select "Clean up in System Restore" at the bottom panel of the dialogue box.
The second method temporarily removes all Restore Points. This one is risky because if something goes kaflooey, you won't be able to undo system changes. It's worth doing if you strongly suspect you're infected with spyware and want to remove every Restore Point before scanning with an antivirus or antispyware program. I've done it, but I'm fully backed up (just like you are, right?).
From the Control Panel, double-click System, click the System Restore tab, and select the "Turn off System Restore" check box. Click OK, and then click Yes to initiate Restore Point Deletion. Do the antivirus or antispyware scan, and then turn System Restore on again: Repeat the above steps, but this time click to clear the "Turn off System Restore for all drives" check box.