This answer would not have worked because CHKDSK /R invokes AutoChk on startup. Anyone that reads the title for this thread noticed the question was about AutoChk not running.
So running CHKDSK /R would NOT solve this particular problem, would just display this error message again. I highly doubt that anyone that has seen this error needs to be told how to make the message show up again.
I'm also running AVG, so I'll get rid of it and run the scan. Of course, the computer will be disconnected from the Internet before uninstalling AVG and until I install it again from its file that I previously downloaded, so as to not shoot myself in the
foot, nor get infected while doing this.
If AVG is the problem, then I suspect that it is using some technique to mess with the Master Boot Record or Partition Table so no malware can install itself there.