I honestly don't know if this is because of a virus, if it's a hardware issue, software issue, or what but my Dell desktop computer keeps "crashing", but it's not a normal crash. I turn it on, it boots up, and then, depending on random things I can't pinpoint, will run for various amounts of time (all very short amounts), and then it just quits. The modem is still on because you can hear it. The monitor is also still on. But the screen turns black, I think once or twice it said "No Signal". A lot of the times the modem fan will start getting really loud and it's trying to do something but I don't think it's a good something... I suspect it's overheating so I then force a shutdown.
I'm having another problem with the computer ("User Logon Service service failed the logon"). They happened at the same time... But I can't be on the computer long enough to even start fixing that because the screen keeps blacking out.