I have selected the option to show hidden files and folders.

The 60 GB discrepancy was calculated with the hidden
files and folders option selected.

I did not have checked the hidden operating system files
and folders. When I check that option, a few more
folders appear, and the count now is only a few GB
more. There still is a substantial amount of space (over
50 GB) unaccounted for.

Is there some utility that checks your disk and reports
errors? I thought Windows Vista had that built in.

Thanks