Basically, I changed all of the hardware in my Windows MCE HTPC and want to reinstall. My issue is, I have 250GB of data I really don't want to move (because of the time it would take). Is there a way ...

Well I have XP pro and in the readme it says in order to perform a clean install you can either have an os installed already (but this leaves you with an annoying "choose your os" prompt at restarts) ...