Internet Security Software

My trend micro internet security software has expired and I currently can NOT afford to upgrade/renew my license. I have two options: 1. My dad has some sort of McAfee IE security from his work for free (bad experiences with McAfee so I'm not so sure...) more details on what version it is later. 2. AVG free version... I have a few questions about it: is it safe and light on the system? Does anyone else use it? Any opinions?
Thanks
Thanks
