The file or directory is corrupted and unreadable
I recently installed Vista, and soon after, I keep getting notifications popping up saying that [insert program here] has detected that my boot drive (C:) is corrupted and unreadable. I have no problems with any of the files on the disc, and CHKDSK came up with no problems. The disc manager says the drive is "Healthy (Boot, Page File, Crash Dump, Primary Partition)." These notifications have become more common, however, and it has gotten to the point where I am unable to install anything, and I get an error message saying something like "Your disc is corrupted," or "The Directory could not be created. I am also having problems with some programs not finding certain DLL files.
What's going on?
P.S.: I am also unable to install Update for Windows Vista (KB941649) and 2007 Microsoft Office Suite Service Pack 1. I get the error message "8007007B." Could this be a related problem?