[StevoRocket]

Oh dear Oh dear - the first post is the one I would go for - new hard drive - New legit XP and use the old C drive as a second drive on the system to give access to your old data/doc/photos/music. - this is exactly what I run now and is the easy one to do without getting into a spiral of complexity and gltches that the average home user could well do without.
By the way I have been a computerite since 1967!
A few pointers though which catch out people -ask me how I know!
When you have XP loaded and are feeling real cool - dont connect to the internet until you have A VERY GOOD VIRUS CHECKER! RUNNING!
AND Try to connect to the internet through a router WITH A FIREWALL!
UPDATE the virus checker files from their web site!
Then - load and update ALL microsoft updates for XP.
Then load Adaware (free) and Spybot (free) and the Microsoft spyware checker Beta (free) and run them every day!

Simple is best - the alternative can be whole days of ever frustrating costly calls to support telephone sites!

Good luck!