Problems with NVIDIA grafic driver and Windows 7 x64

Hi,

I've a PC with a GeForce GT 420 card under Windows 7 (64 Bit version).
The graphic driver version is 8.17.12.8026 from the 03.08.2011 (8/3/11)
the name of the downloaded file was
280.26-desktop-win7-winvista-64bit-international-whql.exe.

I've some problems on my PC, which may be caused by the graphic driver:

The first problem is, that I can't display images with the standard
Windows 7 program - in German it is called "Vorschau" (maybe Preview in
english). Instead of displaying the image only the text "Ladevorgang..."
(Loading...) is displayed.

The second one is, that in the NVIDIA control program (NVIDIA
Systemsteuerung) the rotating 3D NVIDIA icon will not be shown. The
window is blank. On a German system you can find this icon under
"3D-Einstellungen", "Bildeinstellungen mit Vorschau anpassen" - maybe on
an english system under something like "3D Configuration", "Changing
display settings with preview".

3. Until yesterday the Windows Media Center started with an error
message. This message contained the info, that the memory of the
graphic card was lower than 64MB - which can't be true. But at the
moment the media center is starting without any problems.

The Direct X diagnose tool dxdiag displays no problems.

I'm able to start windows 7 not only native but also virtual in
VirtualBox under Linux. In this case it uses another graphic driver and
none of the described problems can be discovered - the second problem
can't be tested in this case.

Does anyone have an idea what could be wrong with the system?


Thanks a lot,

Heiko