Hi, Before I go in to explaining my problem I did a search of this site and found someone else who had a similar sounding problem here: http://www.techspot.com/vb/post164706-4.html However the solution to his problem was not resolved in the thread. I have an Advent T1 (All-in-one pc), it is just over 3 years old, and recently has been having a few problems. Approximately 3 weeks ago I turned it on and everything loaded fine, it went to the desktop as usual. However about 3 minutes after being used the screen went blank (completely off - not just black) and it sounded like the whole pc "shut down". The fans stopped and everything went quiet, apart from the blue standby light remaining on. It went into a sort of hibernation state although it was as if it had shut down as you could not recover it. I had to manually turn the pc off and restart it, once it loaded again the same thing happened - after approx 3 mins usage it would shut down. After several system restores I opted for a complete reformat to see if this would solve the issue. However for the next few days the same thing continued to occur. You would turn the pc on and randomly it would shut down without notice (as if you pulled the plug). However after the reformat the pc would often run for longer, 20 mins to a few hours, before shutting down. Over the next few weeks the pc seemed to sort itself out, I have been using it extensively throughout the day and it has worked fine. However yesterday the same problem resurfaced. I had been using it for over an hour and then, out of the blue, it shutdown. I was listening to music at the time; the screen went blank the fans went off, all noises usually made by the pc when working stopped - the music continued playing though for about 5 seconds before that stopped too. Again the only signs of life was the blue standby light. The problem has baffled me as I cannot understand why it originally went wrong then, for the past few weeks it has worked fine, only to go wrong again. I believe it may be overheating as I am sure its full of dust inside (being an all-in-one pc I havent been able to open it to clean). However i'm not certain. I also read that the power supply may be an issue but again, why would it work fine sometimes then not others? At the moment the pc has been on over 2 hours and it is still working fine, but could go off any minute. Has anyone else had a similar issue or heard of it happening before? Thanks, -Miles P.S. I really should get it serviced, just to give it a good clean out inside, however how possible is it, that overheating is causing this problem?