I posted this problem a few months ago - but no one responded (gee, thanks!). I eventually fixed the problem (or it fixed itself). Well, it was obviously only a temp fix cuz it started again yesterday without warning - I didnt load any new software or replace any hardware or install updates. Anyways, the problem originally started right after a windows update. I was playing an online mpg when the computer just rebooted without warning (no error message, just black screen). It started up alot slower than usual. It seemed to only occur when I used IE, so I switched to Mozilla. After a couple days, Mozilla did the same thing. If I wanted to play the game, I;d have to log in using a third party "toolkit" - which worked for a few days, then it happened while using that too. i tried another toolkit, whcih also worked briefly, then the rebooting started. I can usually do other stuff online without rebooting, but it seemed like whenever I loaded that game, the computer would reboot. Specifically: After I log in, I'd get approx. 2-5 mins of game play, the screen goes black & the computer reboots. This happened regardless of which browser or toolkits I was using. At that time (& again now), I restored the computer back approx. a week to 10 days, ran all the diagnostics/cleaners I have/could find such as windows disk cleanup (I have win xp with sp2), diskchk, Crap Cleaner and Windows Live OneCare. I uninstalled/reinstalled IE 7.0 and uninstalled/reinstalled Java (to the latest update). I even uninstalled/reinstalled the game toolkits (I know I probably shouldn't use these programs, but they havn't given me any problems so far - and I don't believe either program is causing this problem because neither was on my computer when the problem started) I removed the most recent windows updates and cleaned any dust out of the tower. NOTHING fixed the problem! (It stopped rebooting itself for a couple months, so I thought the problem was fixed. Obviously, its not - maybe it was just sleeping! So far, the only time it reboots seems to be when I try to play that game. (yes, I know....the fix is dont play the game...haha but This problem has me very aggravated & frustrated cuz I cant figure out whats going on!) Anyone have an idea what could be causing this problem? Any assistance will be greatly appreciated!!! (I've posted on a couple boards & literally hundreds of people have read the posts, and no one? can tell me how to fix it? I find that hard to believe.) I will take any suggestions at this point. Every time my computer reboots, its that much closer to going out the window - it has me that angry! Please Help! Thanks! I dont know all my specs but I have windows xp, sp2, IE 7.0, Intel Celeron(R) CPU 2 80GHz 2.80 Ghz (mostly Intel inside) 1.49gb ram (I seriously doubt that its a memory problem because it never happened prior to June of this year,). If anyone needs more specific info, just ask & I'll try to find out.