Keeping your PC safe

[complich8]

As a user, there's not much you can do to maintain your system's registry.

Well, there is, but you wouldn't like it. Basically, the best way to do it is to live in a limited-user account, and never be admin. Never install software, except for windows updates and updates to well-known and trustworthy applications. Stuff like that.

Windows itself doesn't corrupt its own registry. If things happen to it that cause problems, it's usually the fault of badly-written third-party applications trying to do things they shouldn't.

That said, if you're a "good" user (ie: use safer software, don't trust unknown apps, etc), even living in admin you should be able to get 3 years or so out of the life of a windows xp install. And by three years from now, you'll probably be shopping for a new computer anyway, and your hard drive will probably be on its way out <_<

As far as what's stored in the registry: everything that isn't stored in your user profile directory. Metadata about everything. System configs (like keyboard, display settings), drivers to load, startup applications, filetype associations, CLSID entries and application mappings for them, local user account info, MIME types, system variables, install paths and application infos, service configs ... it goes on and on. EVERYTHING in your system uses the registry (and if you don't believe it, check out sysinternals regmon.exe and watch what's accessing the registry and how often).