Good day, Should I switch off antivirus program (Avast) while running defraggler ? Or it is not necessary. Thank You for advice....
Temporarily disabling Avast might give you a speed boost, and then again it might not.
Defraggler uses the Windows defrag API therefore most antivirus software should know to not interfere if possible. If this was 15+ years ago I'd say disable the antivirus, but nowadays it's more of a personal choice.
Andavari is right. I think it's not needed the hassle anymore.
and if you do every disable the AV, it would be prudent to also disable your network adapter.