Mcafee anti virus or norton anti virus for windows vista

i know this has nothing to do with model trains but i have bought the latest pc with so much memory etc etc and it comes with windows vista and i have tried loading mcafee anti virus on (which states vista compatible), it loaded up ok but the pc kept crashing on me.

windows vista has some how blocked it ? (vista wont even allow certain games to load up either)
i dont want to keep wasting money on anti virus things that will not load or work on vista.

Now, does anyone here have a super duper pc with windows vista and have norton, mcafee or any anti virus software installed and if so, which one please ? pc world said they wont sell mcafee to vista users becaue of this problem.

the last thing i want to do is get viruses etc etc and i DO NOT TRUST bloody windows so called security !!!!!!

any help please as i would be so grateful.

thank you gang

P.S mcafee is probably the best one to stop hackers,trojans,viruses etc etc !