Personally I don’t even recommend a full system scan, if I wanted to be strict I would say the Quick scan is another that could be left alone too.

  • With a resident on-access antivirus like avast, the need for frequent on-demand scans is much depreciated. For the most part the on-demand scan is going to be scanning files that would be otherwise be dormant or inert. If they were active files then the on-access file system shield would be scanning them before being created, modified, opened or executed.

I have avast set to do a scheduled weekly Quick scan (more from old habit), set at a time and day that I know the computer will be on.

If for some reason my system wasn’t on, no big deal I will catch up on the next scheduled scan.