Window's won't start normally, could it be video/graphics card?

My drivers all seem to be up to date and the computer used to work fine, we've tried reinstalling windows (once or twice) and the same problem still continues. Also tried replacing the C: drive with another harddrive which had Windows Ultimate on it, this worked for a while but then went back to the screen that is the problem.

Safe Mode works but once I start normally it starts up but then at the end of the flashing of the windows logo it says "Not Supported" on the monitor and you cannnot start it normally. I tried Microsoft's "Fix It" help option and came up with "The current video card driver isn't compatible with the Windows Display Driver Model"

The graphics card is Asus EAH5870 (ATI Radeon HD 5800 Series), Asus P7P55D Motherboard and I am also running Windows 7 Home Premium 64bit
Does anyone know if there is a WDDM for my graphics card or how I can fix this at all?

Thanks

go to ATI and grab the latest drivers. that should solve your problem.

Try choosing only the driver during the Catalyst install to avoid the bloatware which itself can be problematic.

Here: AMD Catalyst

If that fails, uninstall and try the beta driver at bottom.

WHile this is going on, keep checking optional Windows Update to see if Win7 wants another driver. Automatically get recommended drivers and updates for your hardware

Well when I tried the beta version came up with an error "Failed to load detection driver" and the other one had a AsInsHelp DLL error

AsInsHelp DLL error is a Cool N Quiet malfunction. Do you have that installed?

Is Catalyst installed in the Control Panel>Programs and Features? If so, try uninstalling it, reboot and then install ONLY the Catalyst driver, nothing else in the package.

If that fails then try reinstalling Catalyst in full.

If that fails post back and google the full text of the error to start reading up on how others have solved it.

no i don't have Catalyst in Programs & Features

windows installer cannot be accessed when i try to install something, how do i fix this?

Sounds like you've got more serious problems. Try working through these Troubleshooting Steps for Windows 7 to see if you can gather more clues.

I was also waiting for the exact wording of the error so we could research it more for you. If you want to fix this it requires utter thoroughness without missing a single step, so if you have questions on getting any steps done ask them back. But don't ignore any more steps.

Please fill in your System specs in bottom left corner of your post.

As a last resort if necessary we can help you get a Clean Reinstall - Factory OEM Windows.