This may seem like the most simplest of questions, and there may indeed be a thread on it already, but here goes. Before running a scan should all open program on my pc be closed. I’ve often wondered if leaving anything running in the background would lessen the efficiency of Avast?
The most effective scan is always a boot time scan.
If you’re saying efficiency as being performance, close the programs.
If you’re saying efficiency for deep detection, well, maybe the thorough scanning (with arquives) could reach further… 8)