Here's the content of C:\Users\UserName\AppData\Local\ESET\ESET NOD32 Antivirus\Quarantine\INFO.NQI:
I don't see any values there, just an "EQIF" header. I tried deleting this file and rebooting but no change.
Count Before:
Adding File to Quarantine:
Count After:
Unfortunately, after deleting the quarantined file the count's now back at 1.
So... any more ideas?