Many anti virus companies have free versions for home users (if you use it as part of a business less so although do check)
Avast
http://www.avast.com/free-antivirus-download
MSE (microsoft security essentials)
http://www.microsoft.com/en-us/security_es...ls/default.aspx
There are quite a few other AV programs although Avast and MSE are pretty good (a few clients use avast although for the sake of my not having to learn another AV program I tend not to use it but I have no justification for pressuring them out of it, other clients I point towards MSE). We had a nice thread around here the other day about anti virus programs too.
I will echo the mcafee is terrible crowd (bad detection rates, high system requirements, heuristics are terrible and it goes on although those three alone are more than enough reason to ditch it). You might have troubles uninstalling it via the usual add/remove programs so
http://service.mcafee.com/FAQDocument.aspx?id=TS100507 has a nice standalone tool for removing it (would be IT types Norton has one too and I keep both on my computer fixing USB drive right alongside the likes of GMER and combofix).