Grb3963

I have an Aopen pc/pentium 4/with 256 ram running windows 2000
I formatted hard drive(40 gig) and installed windows xp professional.
Now the pc locks up on start up(win logo with blue status bar)
It will however start in safe mode.
I now 256 ram is small but it should be enough for win xp to start.
Does anybody know what the problem could be?

Thanks, Merry Xmas