On-access scanning, no doubt, has its benefits. However, it consumes IMHO inordinate amounts of time. My system: a 2000 Sony desktop, a quad VAIO machine at 2.8 GHz with a GBy of RAM. Not this year's Formula 1, I admit, but a simple attempt to start Internet Explorer with on-access scanning turned on takes from 30 to 40 seconds before the Yahoo screen is fully populated, or two count them two seconds with OA scanning turned off. It's nice to be protected,~~BLEEP~~ Is there some middle ground between efficiency and protection? Before someone brings it up, the depth of scanning has no effect timewise.
(Side issue. I complained via feedback about how difficult it was to access this screen. No doubt, I made some mistake or other. Nevertheless, I have no idea how I finally got here to ask this question. Par for the course these days, I suppose. )