Omni 27-1210xt CTO all-in-one running Windows 8.1 Update 1. Built-in Windows defrag is set to optimize all drives on an automatic schedule and all drives are recognized and checked in the defrag scheduler. When optimization runs, all drives are defragged except for the "C" drive -- it's simply ignored -- and I have to optimize "C" drive manually.
I also have an HP lappy, 15-d030nr, also running Windows 8.1 Update 1, and it has the same issue -- defrag ignores the "C" drive but will optimize all other drives.
I have tried a couple of third-party defrag programs and they will defrag "C" drive. However, these programs do not recognize all of the other drives.
I'm stumped. There are no errors in the event viewer and CHKDSK comes up clean. Any ideas or suggestions would be appreciated.