Try again using Safe mode to install the drivers form the NVIDIA WebSite and
be sure you follow the NVIDIA procedures for removing any old drivers first.
Do NOT use WinUpdate to check on or obtain new drivers from MS for your
card. There have been several reports recently of WinUpdate installing new
NVIDIA drivers and causing problems like you one you are having.

"Smilerfive" <Smilerfive@discussions.microsoft.com> wrote in message
news:D1C84BB5-170B-42B6-B774-46F89C20AEB6@microsoft.com...[color=blue]
> August 27th, Vista Ultimate 32bit, Nvidia 7600GT, 4Gb Ram
>
> My Vista Ultimate system has an XFX NVidia 7600GT card in it. It has been
> working fine since the day I put it in. My system is always on and I
> usually
> let it update automatically via Windows Update as required.
>
> The other day I came home from work and began to notice a degradation in
> graphics quality. There were artefacts on the desktop and things were,
> well,
> twitching… I became concerned and then I noticed that Vista was recovering
> a
> crashed Display Driver repeatedly (first I had ever seen that) and then I
> was
> really concerned. I had not updated or changed anything myself so I
> started
> to check Windows Vista Update to see what it had updated in my absence. I
> only managed to begin to see that Update had downloaded or started to
> download, among other things, an updated NVidia driver..
>
> I never got a chance to fault find any further since my system then became
> so unstable the graphics went for a loop and I could not make anything out
> on
> screen. Next thing it somersaulted into a BSOD blaming nvlddmkm.sys
>
> Now my system will not boot up and immediately crashes with a BSOD every
> time blaming nvlddmkm.sys – an nvidia display driver. The only way I can
> get
> into my system is via safe mode and it has limited tools, particularly, it
> does not allow access to Windows Update for me to check what Update did,
> what
> it installed etc etc
>
> I don’t know the version of the driver that was working fine previously. I
> had never updated it since the card went in and it has worked fine ever
> since, that is until this recent event. I don’t know what version Windows
> Update tried to install because I can’t check it out.
>
> What I’ve tried:
> Installing a variety of updated drivers from NVidia Website including a
> beta, from Safe Mode in Vista: no result, same BSOD
> Rolling back driver to previous: no result, same BSOD
> Using Sys Restore in Safe Mode to jump back to a previous known good
> position: no result, same BSOD
>
> Basically my system is trashed because Update downloaded some monster
> driver
> that screwed up my system. Usually I’m pretty good troubleshooting and
> fixing
> these kinds of things, I work in IT, but this one has me stumped. I have
> no
> idea what Update did and feel I have exhausted my troubleshooting options.
> Can anyone help me? Thanks.
>[/color]