I had the same problem w my computer. I tried everything and i could not find an answer on Google anywhere. So I rebooted my computer (that is I reinstalled the operating system). Unfortunately, after a while, the error came back...
I had heard that having multiple antivirus software on your computer can cause problems, and I had both Symantec and McAfee antivirus on my CPU. I found out that the APQ files are copies of quaranteened and infected files kept just in case they happen to be critical system files. I figured that McAfee might also keep a copy of infected files.
I haven't examined any code, but I'm guessing that Symantec thought McAfee's copies were real hostile files so it copied them to its APQ file. Then McAfee thought Symantec's copies were hostile files and copied them to its temp file. This probably went back and forth in an infinite loop.
Therefore, the last time I got Symantec reporting a hostile file in APQ, I removed McAfee from my computer, and when I restarted my computer, Symantec reported that it had finally killed whatever was in its APQ folder. Full System scan reports that my CPU is clean.

. So make sure you only have 1 antivirus software on your CPU.
(I did this literally yesterday so the error message may come back but I doubt it.)
