OK, heres the summary. Just rebuilt my computer and reformatted & reinstalled Windows 2000. Now I have a Athlon XP 2100+ processor, however when I boot up it says I'm running a Athlon XP 1500. I then go into BIOS and change my CPU speed from 100MHz to 133MHz. I save changes and reboot. Now it says I'm running a Athlon XP 2100+, okay good. However when it goes to load Windows I get a blue screen with some error. I reboot and it's still there, which only leaves me to go back into BIOS and change my CPU speed to 100MHz. Any help is appreciated.