Replacing Vista with XP: problems

I bought a Gateway MT3422 laptop. I'm trying to install XP on it instead of Vista, to try to improve performance (it's not nearly powerful enough to run Vista well).

I format the hard drive and install like normal. All the system files seem to copy over fine (except for one .dll file related to IE, which I plan to uninstall anyway), but after it restarts to do the setup portion of the install process, I get an error about "Insufficient System Resources Exist to Complete the API", and the computer reboots, continuing to do so every time in an endless loop.

I tried reformatting, this time using the full format option (rather that quick format), but it still does it.

Any ideas about what to do?

Also, /g/ is a bunch of faggots who would rather just insult me than provide an answer.

It seems to be working now that I'm using my legitimate XP installation CD instead of one I downloaded off the internet. I guess I'll have to buy another copy of XP if I want it on this machine (it'll only cost like $14 through MSDNAA. It's how I got the copy I already have, after all). Or else find a way around WGA...