NTRegopt, or NT Registry Optimizer

Windows NT Registry Optimizer, a program out of Germany. Great little free file (contribute if you wish) that does a great job of fixing the Windows NT, 2000 and XP registry. A lot of these programs cause more problems than they fix, but this one is conservative and seems to work pretty nicely. I run it fairly regularly.

If your NT-based Windows OS is starting to get flaky, run this program right away. I've nipped many a problem in the bud by running this program as soon as a weird problem developed.