System Crash and Reboot

My system crashes and reboots almost every time I use it. If I’m playing music, I get the stutter, then crash and reboot. I may have Real Audio open and a window or two surfing the net. I’ve doubled my memory to 1024 and have plenty of space on my harddrive.

I have XP Pro w/o SP2 (because it won’t install-says it can’t validate product key). I have XP Home I want to install since I think my problem is a corrupt XP Pro or possibly a pirated one.

Is it possible to convert from Pro to Home and do I have a correct assertion that its a bad XP Pro that’s causing the crash?