09-22-2017 , 05:33 AM
Given most AV's do scan immediately after installing its highly likely any thing malicious running in between will be caught, unless I decide to give it a few days before installing new av. I usually uninstall, disconnect from net & restart but don't install new av straight away, do defrag jobs etc, make a backup image. Then in the evening install new av & scan. Hardly any threat shows, a few false positives sometimes. Don't plug in usb or ext hdds either in the in between period. Secondary AM program like malwarebytes/emsisoft remain active during th e period anyway. Zemana/Heimdal as 3rd line of defense...