Bob, you may recall that after I couldn’t get into Windows and ultimately was able to do a restore, Windows thought that my C: (boot) drive was still 200GB, even though as part of the process of getting back into Windows, I’d wiped the drive and created a new C: partition of 300GB. At that time, I left the rest of the drive unallocated.
A few days ago, I finally changed that to drive D, but haven’t used it yet. Despite the fact that the drive only contains $RECYCLE.BIN (129 bytes) and System Volume Information (0 bytes), File Explorer showed that 228MB were being used. I low-level formatted it, and now it shows 277MB are being used. At one point (before the format), it showed 100GB as being in use!
My File Explorer view options are to show hidden and system items.
It’s a primary partition, but not active.
AVG doesn’t find any malware.
I don’t know what else to try.