It's one of the work pc's, a bit old like 6 or 7 years. We're soon going to get a replacement for it, but I am still curious as to the cause of this problem: Like once a week, it freezes. It just freezes, I mean the monitor still shows the desktop or the accounts program. It doesn't BSOD. Mouse pointer doesn't move, ctrl-alt-del doesn't work. Then if you switch it off and on again, it doesn't boot. No beeps, no post, monitor remains on standby, and on the case both green and red leds remain on (normally only the green one remains on, the red one works during hdd activity). The solution is to open up the side and give it a good blow with compressed air. Now the pc is very clean inside (I use the compressed air on it like once a week) so it's not a dirt problem. Any idea what could be happening and why the compressed air makes it work again? Any clue as to failing hardware? According to speedfan the CPU idles at 56 degrees... it's an Athlon XP 2600+ However I doubt that this problem is directly related to CPU overheating because even if I leave the pc unpowered for an hour or more and it cools down, it still doesn't boot unless I blow it with the compressed air. Thanks for any help.