You DON'T need to regularly re-install Windows

Says Life Hacker. With a regular cleaning regime and some habits, like not installing every junk application you see, you won't need to have to keep re-installing Windows every few months/years (like I have). Check it out from Life Hacker.

Update:
You REALLY don't need to re-install Windows.. After running CCleaner, my entire Win XP system suddenly ran like a newly-installed OS all over again! Proven, and I didn't even bother with the configurations, I just ran it stock. Awesome stuff.