Windows 7 is really great man keep it for a few days and customize it (I have it and I have no problems with it.) Pm me if something frustrates you about it I know allot in that field. + incompatible programz can run on windows service pack 3 by right clicking and trouble shooting with the administrative options.

If you reeeeeeeeealy want to do it here ya go:
What you need to do is get a copy of  windows xp online or from an electronics store (in CD format) once you get your CD slip it in. Restart you computer and smack F-12 on the boot screen it will then ask you from what place do you want your computer to boot up from (CD drive or hard drive) click on the CD drive and your computer should take care of the rest. I'm kinda dumb with computerz so I could be wrong but i have installed windows 7 into my friends lappy that way.

I hope you take everyones advice bro.