You click "Disk Drives", then rightclick your drive. It won't say C:. C: is
the Volume, which is seen another way. Your drive will have a device name,
like XX123456. The Properties of the drive will show a "Policies" tab, and
you will get a checkbox for the "enable write caching on the drive", which
you want to uncheck, since it is failing for you.
If you want to actually see the C: volume info. "Populate" the "Volume" tab
of that device Properties. This, however, has nothing to do with the delayed
write problem.