For months there has been frequent (several times/day) instances where my system seemingly hangs for 3-5 minutes, during which time there is more-or-less continual hard drive activity plus my cable modem shows nearly constant send/receive activity. By 'hang' I mean that the browser (either Internet Explorer or Firefox) will not respond to any commands during the period; and any other program I'm in will be extremely sluggish, waiting 30 seconds or so to respond. This is far too much foreground activity for automatic updating, which happens in the background and interferes only slightly with my work (if at all). Zone Alarm Extreme Security scans do not detect any virus/trojan/worm. I do not find any unexpected events in the Zone Alarm logs. I think this is the sort of behavior that would occur if my system has been commandeered by a very sophisticated, 'stealth' spammer or other malevolent actor. I am clueless about how to troubleshoot this situation, and will appreciate expert assistance. I am an experienced PC user, but not deeply knowledgeable about this sort of thing. Aloha.