Vista - Start menu refuses to open, other various issues...

Last night around 2am (4/5/08) my Vista decided to install a few updates and reboot itself. Upon booting back up, I was severely dismayed to discover that my start menu refuses to open, and at least one other (seemingly random, and non-Windows) file had been deleted.

The start menu issue seems to be the most pressing problem, anybody have any ideas?

I attempted a system restore, which was successful, restoring back to 4/3/08, but the issue persists. It very well may have been a corrupted update file, but I'm not sure of how I would verify that or remedy it.

I've also noticed that, although I can explore the start menu through a simple right-click, none of my programs are showing up under the "programs" folder. I have the standard Accessories, Administrative Tools, Maintenance, and Startup, but none of the other options I would otherwise be expecting.