Ok, I just restarted and it does scan on start up. Only thing though, it scans the objects that run on start up, so it doesn't scan your whole harddrive at start up, just the programs that load at start up. Which doesn't even phase my start up on 384 MB of RAM. And you can disable that sound notifaction, just go under KAV, then go to Settings, Additional Setting, and untick Enable Sound Notifaction.
Bookmarks