Windows 7 Home Premium black screen after POST

My computer is running Windows 7 Home Premium x64 and after POST it goes to an all black screen with a _ in the top left.

This started with a blue screen after waking up from sleep. I have re installed windows 3 times now and it happens again after 2-3 days always the same after waking up. It will boot ant thing else i can think of from UBCD to Linux and the install CD. The install CD however will not run Start-up repair saying it is not the right version of windows even when i installed it 2 days ago with that exact CD. i"m normal very good with computer but this one has me stumped and i don't wish to re-install again as it takes quite some time as it is a rather unique setup.

Thank you for any help you can give
Bradley

all black screen with a _ in the top left

That could be any number of things such as it trying to boot to an Optical drive that has a disc in it but is not bootable, has a USB drive plugged in or a printer with memory stick slots or USB port on it. Basically it's looking for boot files and can't find them, could be the HDD has gone bad.

It is not as i said i'm pretty good with computers and I'm sure it is the right drive.
The hard drive passes all smart test.

Work through the steps for Troubleshooting Windows 7 Failure to Boot.

Compare the install you did with the perfect install compiled in Clean Reinstall - Factory OEM Windows 7, especially how drivers are handled in the first driver-complete OS - which is much different than XP.