I decided to run a check on my PC today and run Ad aware, Spybot, and my Norton AV. when running, ALL three crashed my computer half way through the system check. I did another restart of Ad aware and it completed the check OK (nothing found), but Spybot crashed again. I haven't tried Norton again, but for what reason could this happen, hope someone has an answer. Apart from this, my PC seems to be running OK??? OS XP home.