Hello all, I'm sorry if this is in the wrong forum as I'm not sure what the problem is! I'm having a MASSIVE problem with my computer and as usual it's happened at the worst possible time (need to complete and send off my job application today) so I'm really panicking. What's happened is this; Monday morning I turned on the computer, walked off and came back with the desktop loaded. Itunes was up as my ipod was plugged in to one of the two front USB ports but the ipod screen was not lit (which is unusual). The computer had crashed, totally frozen as even the mouse wouldn't move. There was a very short line of pixels next to the mouse that were shimmering, I've not seen this before. I turned it off at the main switch then shortly back on again. The fan would go and the disk drives would whir but there would not be any output to the monitor or any other response. I called a technician to come out and he first took out and reinserted the ram card. The computer turned on after this. He plugged his pen drive into one of the front two USB ports to look at the .dmp file on his laptop and the computer instantly crashed and rebooted- I've had my pc for 18 months and it's never done this! He then swapped the ram card into the other slot. It started and didn't seem to crash. He ran a program that tested all aspects of the computer to see if it would crash under pressure but it didn't. He was able to look at the .dmp file and found it was a windows system error that caused it to crash. It's been fine since then until last night I plugged my scanner into the front USB ports and it froze again with the same wiggly pixel line by the mouse. And again, after this it wouldn't turn on. I took out and replaced the ram card- nothing. I had turned off my scanner but not unplugged it, I did this and the computer started. What I noticed was different is that only one of the three lights on the front of the tower were lit when it wouldn't turn on, then all three when it would. I sadly don't know what these lights are for! That's my next line of investigation. I carried on using my computer happily, it even survived a restart after I needed to reset my wacom. Then this morning, it's the same; won't turn on. No USB cables are plugged in (I decided not to use the front two ports at all) and I've tried both reinserting the ram card into it's slot and swapping it to the other one but still nothing. I know it's not the PSU as the tech guy tested the one I have and it tested fine but he also replaced it with a new one to make sure and it still had errors. History of this comp; had problems loading the desktop after the windows screen (it would just go black). Seemed to be related to my wacom being plugged in on start up and read others have had this problem with digital cameras plugged in at start up. But then one time it really wouldn't load up/start up. Followed microsoft online instructions and that totally fubared it, had to format and reinstall. Since then it's not been the same machine. Very slow, bad graphics and play back, like it had a lobotomy. Irony is this version is a legitimate version of windows, not a crack like it was before format. I've never had any other problems with it. Please, please help me if you can and tell me what i need to do/buy to replace as I'm so totally up **** creek without a paddle if this computer doesn't turn on again today! I really appreciate anyone for simply reading the above and for trying to help me. I hope you can!! Thank you. p.s. Oh, it's an Acer 7500 if that helps.