Computer frozen

This could be any number of things, from processor to RAM to video card to motherboard. If you have a spare system, I would begin swapping parts among the two to see if you can track down the source of the problem. I tend to believe it is not the RAM or video card because you would have gotten audible beep error codes. In my experience with similar issues, I'd bet the problem lies in the motherboard.

You also could check the fan on the cpu. If it isn't working properly it can cause the cpu to overheat and that creates similar problems.

Boot up into Safe Mode (if OS is Windows). Check System Properties, Device Manager, and see if anything is conflicting with something else. If so, fix the problem.

I run WindowsME. On occasion the boot up will go to a blank screen but still loads. You can tell this by the light for the Hard Drive. Afterwards I go through the same process of shutting down as if seen on the screen. Start Menu (by using the Windows keyboard button for bringing up the Start Menu), up arrow one time, Enter for Shutdown, then Enter again to Shutdown the computer. Odd yes, but works, otherwise you keep shutting down till the Boot sequence restarts itself correctly.

You should reboot though into Safe Mode. Either the F8 or holding down the CTRL button on bootup. Check for conflicts. If reboot okay start checking the Video Card for updated drivers, check everything you recently downloaded (remove if think it is the problem). Do a Windows Update. Check drivers for hardware. Do a Scandisk (Fix Errors Automatically), Defragmentation, and reboot. If have Norton Utilities run the Norton WinDoctor and Norton System Check. If do not, get it and use often.

Hope this helps.

1 more test. What if you have MBR of your HDD corrupted. Try to set boot order in CMOS to define drive A or CD as the first. Then try to boot your PC from floppy or bootable CD. If OK, try to recover MBR with the help of, say, DM, or format C: if data on your drive was erased by a harmful program.
If not, goto the first answer.

It's more likely your video card. Try clean the contacts with a pencil eraser and reseat it or better yet try another card if available.

This question was auto closed due to inactivity