system
20
i suggest windows defender (for free resident protection),now it shares most definitions from microsoft security essentials which has been found high in detection in the recent tests conducted by avcomparatives… many in this forum complain its waste & also interfere’s with working of avast. but i never had a problem with it for 4 years…also it notifies u when services/drivers are installed, registry modified and IE page changed!!
it gets updates every week too