original problem

my son plays on runescape and now my computer kicks off whenever he's playing & makes this beeping noise until we turn it off. We made him quit playing.

bigger problem
now, my computer kicks off whenever I try to run my antivirus/spam

I have AntiVir PE for anti virus and spybot for spyware removal.

I have tried running these in safe mode & it still kicks off & starts beeping until we shut it off.

I tried running http://housecall.trendmicro.com/ and you guessed it, it kicks off & starts beeping
(I hope I'm calling it the right 'kicks off' and 'beeping' I don't mean to sound dumb here!)

how can I get my antivirus/antispam to work with it kicking off?

I can get online & everything just fine (other than runescape), what can I do?

thanks ahead of time.

*I don't know what all I need to include to ask this question I hope this is enough