Question:
I have been having this problem about once a month now. It seems to correlate whenever Windows 8.1 Pro updates or is searching for updates.
When I initiate a virus scan (e.g. quick/full, ect…) the scan begins, but abruptly stops after about a second. Avast then reports that the scan is complete and “NO TREAT FOUND”. Normally a full scan takes over an hour on my machine, a quick scan is not much quicker.
During this time the computer is a little slow and the hard drive is more active than usual.
Further, I noticed a couple of Windows notification pop ups appear by the taskbar, but they appear and disappear so quickly that I don’t have time to read them. (Is there a log entry that records these so I can see what they were?)
These symptoms last for about a few hours. Afterwards these symptoms disappear. Avast then scans normally, and the lag in my system is gone. When Avast does perform its Full Scan, it reports “NO THREAT FOUND”.
I have scanned with Malwarebytes and it too reports no problems.
Avast is the only real time security product I am running.
The only correlation I could find is Windows Update because I recall on the last few occasions of this occurring, Windows was looking for updates. I am not sure if this problem exhibits because of Windows looking for updates or perhaps due to something more serious.
Any ideas would be appreciated. Thank you.