I have a Dell Optiplex GX280 and I have had some freezing issues and it has wanted to reboot on it's own for no reason frequently. I thought it was some malware that I couldn't detect so I was in the process of backing up my system when the really bad problem came up. Now when I try to reboot the computer, the cpu fan runs faster than I have ever heard it. It sounds like it will literally fly apart it is running so fast. I can get no screen whatsoever and it will not boot; not even in bios. I have read several posts about boot problems but I haven't seen anything about the cpu fan running so fast. When I try to boot the computer the light comes on it the front and of course the cpu fan comes on but no monitor signal and no boot at all. I have no control to try and help it. It has the fan shroud like the Dell's are popular about having but I have removed it with no luck and put it back on. Once the fan came on normally and it booted up but I ran Tune Up Utilities to check the system and it crashed while running the scan. I haven't been able to boot it in any way again. When I push the button to start it all I get is the cpu fan running full force and I mean like nothing I have heard before. I can let it set for a while and it makes no difference. I am running a sata 120gig hard drive and 3 sticks of 1gig each ddr2 ram. I recently had trouble with a video card that I had used for as long as I've had the computer and removed it but now my problems are worse. My power supply is only a 250 watt that came with the computer. I have tried removing and changing the ram memory but no effect. If anyone can help me please do because I have a problem that keeps me home bound and the internet such as e-bay,etc is my only income and I don't even have a backup. I am using a friends computer to post this.