You trash McAfee, uninstall it, demand your money back and use something else.
But seriously...I'm running McAfee on three different PC's. Although they are various configurations, and age, it has bogged down my usage to nothing. I can't do _anything_ for 10-20 minutes after starting any of the three, and g*d forbid I try to run any new software. Forget about it working for ages until McAfee has stumbled over it!
I've had no such troubles with just about any free product I've run. And Symantec certainly doesn't bog my system down like this.
I just uninstalled it.