I used Kaspersky for a while but there's a bug with it, maybe with my mobo only =/
everytime i use and p2p sofwares when switching on the Anti virus especially bit comet, my pc will reboot with the blue warning screen. whihc made me wasted my money on 2 new rams, 1 new PSU and 1 week of RMA for my mobo =/
swtiched to bit defender now , performing much better than ksapersky i'd say