I have noticed that some of the services on my computer have stopped without me having any input. the three that have been a problem is Bakground intelligent service,windows installer, and microsoft security center. I put them on auto and started them but when I boot up at a later date they have been stopped I have windows xp home with sp2,and have avg, zone alarm, spybot, adaware plus windows defender. All are updated and used frequently. any help would be appreciated.