Save everything you want to save on a cd.. or backup hd... Restart the computer.. Press f2 to go into bios.. Change the boot order to boot form cd first.
Restart and pop in the disk and follow directions. Easy!
ok i got it to safe mode system restore somehow. now it boots win xp and then when i got into my user name its fine. but then i try finding the new drive i installed and its not there. what do i do?