I'm having problems with my son's PC. He kept gettin virtual memory errors in a game and the game would shut down. I went into system>>and changed the visuals to max performance (instead of let computer choose). That's the only thing I did. We tried to run defrag, but it said dskchck was scheduled to run (and it wasn't) so it wouldn't defrag. Now - After rebooting after I did that, the computer starts up and then goes to a grey screen before it loads the OS. I've tried every option in the F8 and none of them work, they all still go to a grey screen and nothing else happens, no matter what I try. I've tried booting from a restore CD and still nothing but a grey screen. It won't even recognize the restore Cd. Is the harddrive blown? It's like there is no OS on it at all. Please help!!

Harddrive manufacturers have software for download for testing HDD. Memory(RAM), test program for downloading: http://www.memtest86.com/

...both of which are of limited value if Healersmoon is unable to boot the OS... ...I'd say it's likely to be the display settings. After all, that's what you changed. It's trying to pump out graphics faster then the machine can handle. I'd be trying to get the PC to automatically tone down its graphics by booting in safe mode. That loads only the most basic drivers the OS needs in order to boot. Then you can adjust the resolution, colour settings and refresh rate to basic settings and then reboot normally. Otherwise it's likely to come down to alternate display adapters and so forth which can rather involved.

"both of which are of limited value if Healersmoon is unable to boot the OS..." Heh - don't suppose you've ever used them then Typically those kinds of diagnostic programs are self contained, and boot from a floppy or CD If the system is unable to boot from any kind of boot device, then there's not much hope of repair - possibly a motherboard issue, but the recommended practice is to disconnect everything but the bare minimum, see if the machine can be started and then start reconnecting components (or running tests) We've heard that a million monkeys at a million keyboards could produce the complete works of Shakespeare; now, thanks to the Internet, we know that is not true