Vista - Host Process for Windows Services Stopped Working

All of a sudden I am getting the general Vista error message: Host Process for Windows Services Stopped Working. When that closes, a "helpful" box pops up and tells me I might have a hard disk problem. Ran CHKDSK on the drive, no errors.

Going to the event log, I see that when the error message occurs, it points to this file: AgApplaunch.db. I don't know if this file is corrupt. I checked and it is in the Windows/Prefetch directory.

I have had the system for two years, no new changes. I first noticed the message a few days ago after I had tried to install two important Vista updates. As they were installing, the system shut itself off, and I started getting the message upon startup.

If anyone knows a resolution for this problem, it would be most appreciated.

If not, two questions:

1) Can AgApplaunch be re-installed? Either from the web or the Vista disk.

2) Is there a better disk check utility in Vista? CHKDSK ran for about 20 seconds.

Thanks!!