Vista Update Snafu (please help)

I am having trouble with vista, and I am stumped; hopefully one of you out in the ether will have some idea of what's wrong.

I am running Vista 64 Home Premium, and up until now it has run perfectly (as well as a windows product can run). Earlier today, my computer downloaded a windows update, KB929777, which needed a shutdown to complete the install. I wasn't aware that the update was lurking in the shadows waiting for a restart, and I installed the latest nvidia beta driver for my 8800GTS 320 (175.16). The driver install wanted to restart; I graciously let it, and the windows update installed during the shutdown.

When the computer restarted, I was presented with the usual login screen, and when I logged in, I found that all of my display settings had changed. The background was a generic bright windows theme, my usual font was different, all of my pined start menu items were gone, and the quick launch bar (next to the start button) was activated (although I had deactivated it months ago). I also found that I was denied permission to change the settings under the display settings. I could, however, still run all of my programs.

Later, when I again logged onto my user, I got an error that windows couldn't find (or I didn't have permission to access) c:\windows\system32\rundll32.exe. I also found that I couldn't run any programs at all, open the control panel, properties, nothing. I keep getting a message: cannot find whatever.

What is strange (aside from the above) is my wife's user, which does not have administrator privileges, runs perfectly. All of her settings are unchanged. I can run any programs I need, and adjust any settings (assuming I enter my admin password).

So, what the hell is up? I tried uninstalling the video driver, which (not surprisingly) didn't change anything. I have not tried uninstalling the update or "repairing" windows with the install CD because I don't want to accidentally make it worse. If anyone has any suggestions, I would appreciate it.

do restore