I'm running winXP pro sp1. About 2 weeks ago, while happily using the internet, my computer just suddenly powered down. There was no warning at all, and no error. One minute I was browsing, the next, silence. No case fans, no PSU fan, no CPU fan. The only sign that my computer had in fact been on was the powerlight on the front, which was still lit. Other than that my computer was dead. not even the reset button worked. OK, hold in the power button for 10 or so seconds, release it, press it and it starts up again. It POST's perfectly, I select my OS (win XP pro). It loads without problem towards the login screen as expected, the screen goes black, with a white mouse cursor in the middle as normal, It becomes an eggtimer, as usual, then....... .......powerdown. this process repeats a few times. It always powers down just before the login screen comes up. I reboot into the recovery console, and run <chkdsk /r>. About 35 minutes later, it finishes. I reboot into XP again..... ......powerdown. At this point, I'm annoyed. Luckily, I was planning a re-install, so everything that I wanted to keep had been moved to a folder on a seperate partition. I re-installed from an image I took 6 months ago, which I know to a clean copy with only a couple of programs installed. This served me well without any problems whatsoever for about a week and a half, up untill an hour or so ago.... .....powerdown! argh! I am at a loss. I have no warning before it happens. I can only guess that it isn't hardware related, due to the fact that after a reinstall, it's fine with no problems at all. I can't get at any log files because I have to restore an image to get up and running again, thus deleting the previous installation. Is this something anybody here has seen before? My best guess is either a virus, or a startup process shutting me down, implying a hack. Both of these while possible, are obviously not all that likely in the grand scale of things. Any help would be appreciated.