that's the dumbest thing I've ever heard - not formatting ur hdd when installing a new mobo?! For starters expect to encounter soo many problems, the 2 different sets of chipsets are gonna confuse themselves, even if you've removed them in devicemanager (which I'm pretty sure is the most unstable thing you can do lol) XP (even with it's plug and play shit) is still gonna have ur old mobo in it's driver database and due to the fact that you've used those drivers before It'll prompt to install your old chipset drivers (by default)if it cant find your new ones, Yeh; it's perfectly possible, but not worth the risk, that's my opinion. If you do a clean install XP will be nice n fresh so you're gonna take advantage of all that new CPU power, whereas if you were to just slap ur old hdd in that'd be the bottleneck; chances are you wouldn't notice any significant improvemnt.

*rant over*

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