Windows 7: Nvidia card doesn't work for some reason!

I have a problem with my graphics card. I dont know if its borken or anything. It just doesn't seem to work. One day my computer just crashed. Than I shuted it down suddenly. Than when the computer rebooted the videocard drivers didn't seem to work. I unistalled and reinstalled the drivers and same problem. Everything seems to work, but I can't play any games. Every game throws a error message at my face. Most common error is the D3D9 error. I am not sure that my nvidia graphic card is borken or maybe its a overheating problem. I am really not sure. Anyway if anybody has got any ideas, please tell me.
Operating system:NVIDIA GeForce 9800 GT, windows 7 ultimate 32-bit
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The D3D9 error can be fixed by installing the latest DX9 runtime from Microsoft.

Download details: DirectX End-User Runtime

Thanks for the quick reply Dwarf, but saddly that didn't do the trick, still the same error.. I think I have all the devices up do date so that I could play just fine. There are may other errors that I get when I try starting games, that say that something is wrong with my video card. Like I said before everything worked fine before the restart, so there has to be a problem somewhere else.

What games are you trying to play? Many games that require DirectX come with the version that they require on the CDs. Try installing them from the CDs as well.

Have you tried system restore?

If not then type into start menu system restore, click on it. When it comes up choose a time and date prior to your crash then select restore.

I have done system repair, it didn't help. None of the games that worked before the restart don't work. And there are alot of them. I mean Borderlands, conviction, dead space, hinterlands, age of pirates 2, gta 4 and so on. And there is one other thing, which I really wouldn't call a problem (Shown in the picture 1). If the bar is invisible everything is okay, if white, the problem. At first when the problem occured, the computer worked fine a couple of times when rebooting but the problem came back, and now it has stayed that way.

from your snip,i suppose this issues comes from your graphic card itself of Hardware issue i'd say. can you access dxdiag(run type dxdiag and test your graphic card) or device manager to check if your graphic card is detected and check if any driver issue(yellow or red x)

Well I did the dxdiag, nothing wrong there. But at the device manager the draiver did have a yellow warning on it. It said that windows blocked it. Why? I don't get it. I get the feeling that windows blocks the video card drivers for some reason.
PS:Oo I also forgot to write that when I first experienced the problem I found out that my BIOS had chanced during the restart from the place where I can pick the onboard video card or the regular. So I chanced it back. The computer worked fine for a day than the problem came back. So I hope this will help you help me.

Have you tried removing the the video card drivers, then remove the card through device manager, reboot, reinstall everything. See what happens.

Good luck

Do you even have the nVidia drivers installed? You'd get directX errors if the machine had reverted to the generic VGA drivers.

The snaps that you posted are nearly unreadable. I can't tell what sort of drivers you have in place.