I upgraded to XP Pro from ME a week or two ago. At first everything was fine. Then about 6 days ago my brother turns off the computer without shutting down - he just presses the power button. When I try to boot up, it says that my windows\system folder is corrupt. I tried everything, had to reinstall XP. Just now, I had to reboot because some programs were getting unstable (after 5 days of uptime). When I boot back up it tries to pull the ol' scandisk routine. I let it go and when it's done my computer hangs. After about 5 minutes it suddenly reboots. When it comes back it says something about windows not booting correctly last time I started it and lets me choose safe mode, start windows normally, or use last working settings. Both start windows and last working settings do the same as above, and safe mode freezes at the file Mup.sys. The last thing I did before the reboot was send an error report to Microsoft when Windows Explorer had a critial error. Maybe something got messed up there?