Hi everyone. Shame my first post has to be a troubleshooting one but here we go: My machine: first generation intel iMac, 2 ghz processor, upgraded to 2 gigs of ram, circal summer of 2006. Using OS 10.5.6 and Windows XP pro, corporate edition. The problem: Every time I try to log into windows, the machine reboots as soon as it reaches the desktop When I first installed bootcamp/windows, I had some trouble but once I figured out the mistakes I was making during installation, it ran normally. That was a few months back. The other day, I go to use windows for the first time in a month or two ( I really only use it to play Fallout 3, and I've been too busy for it until now ). I try to log in, but my keyboard and mouse don't work. After multiple restarts it's clear that there's a problem, so I go online, research it, and find only two solutions: a repair install of windows, or a complete format and reinstall. After repeated attempts at the first, I ditched my scratched up windows disk and got a new one, and started with a fresh reinstall after I managed to back up my files by accessing the partition through OSX. The reinstall went normally, and everything was fine until I went to restart the machine after installing the bootcamp drivers from my OSX dvd in Windows. Reboot, log in, and then about one full second after reaching the desktop, the machine reboots. It will automatically start in windows, unless I go back into OSX via holding option and selecting it, then reset my start up disk to OSX. Every time I try to get into XP, the same thing happens. I google it but find nothing, save the one point that disabling the automatic restart in case of error during startup function does not help. After multiple reinstalls from my own new copy of XP and a friend's different version, I get no changes. Today, I downloaded an updated driver set from apple.com: I install XP again, install the drivers from my OSX dvd again, and then use the downloaded driver updater to update the drivers. Then I reboot, this time using F8 to disable the auto restart, just for kicks: surprisingly, the computer starts up and logs in normally, and I use windows for a few minutes to make sure it's not going to restart. I reboot into OSX, copy over the files I backed up, then attempt to go back into XP. And of course, the problem's back again. I wipe out the hard drive, and start over, thinking that maybe if I permanently disable the auto restart, it'll solve the problem. It doesn't: this time, it's back to how it was before, and I have yet to get another successful session out of it besides the one mentioned just above. The last thing I tried was booting it in safe mode, which didn't work: instead, I got a screen full of lines that read as the following, except for a different .sys file name at the end of each line. The one written below was the last one on the list, before the screen froze and I had to reboot via power button: dumbass computer posted: multi(0)disk(0)rdisk(0)partition(3)\WINDOWS\system32\drivers\mup.sys At this point, I'm out of ideas. I've seen similar issues posted on other message boards but as of yet no concrete answers have come up.