A friend of mine referred a client to me. We'll call him ``Don.'' Don's story sounded pretty typical -- he was always having problems with his computer. Preliminary descriptions sounded like typical Win95 mishaps and minor difficulties. For example, it was clear some of his file associations had been automagically changed from what he was used to.
As it turns out, Don's Windows95 Registry was corrupt. For those who don't know, the Registry is the heart and soul of Windows95 and NT. It consists of two files that control nearly every aspect of the system. The files are called system.dat and user.dat and are usually in the Windows directory (er...folder) on the hard drive. There are also two backup files called system.da0 and user.da0.
Most users have no idea that these files even exist. However, it's a darn good idea to periodically back them up to floppy disk. (Details are in the back of your Windows95 manual. You can also find this information at this link) Unfortunately, Don didn't know anything about this and his Registry was being reported as "corrupt" by Windows. This meant that the two failsafe files on the hard drive were corrupted as well.
Without an uncorrupted floppy backup of his Registry to restore it from, I needed to do a fresh installation of Windows for Don. It's possible to restore the Registry through hand-editing, but it's far safer and cleaner to re-install.