AV and Firewall driving me crazy

I have tried several internet security products on both myhard drives and they are revving the hard drive and making everything very slow. I use to have mcafee with no problems. The new one I got started making this problem. I tried zonealarm, AVG and now TrendMicro. Each one does the same thing. I have run diagnostics on everything and everything passes. I have Dell Dimension if that means anything. ANy ideas? TIA!