Computer Freezing during full virus scan

Over the last few months I have not been able to run a full virus scan. I have MacAfee and my subscription is up to date. Every time I run the full scan it freezes up at 91 or 92% complete. I have tried running the scan while nothing else is running on my computer and it still freezes. I have taken it to the computer people at my school and they did not find a virus. I also ran Ad-aware scan, i was able to run the quick scan but it froze when i tried to run the complete scan.

I am runing windows vista 32-bit on a dell 1310. It is only a year old, and it is running really slow.

Any help would be greatly appreciated. I don't want to reformat but i'm not sure what else to try.

 

Since McAfee is a paid program and you are up to date, have you either emailed or done an instant chat with tech from McAfee to get the freeze during a scan fixed? That's the first place to start.