Em, I recommend that you get ESET's NOD32 Antivirus. It's not free, but it's head & shoulders above the freebies, especially when coupled with MalWare Bytes to curb the non-virus issues designed to just be a pain, slow your system, or flood you with pop-ups. Freebies aren't kept up to date as well as the ones you pay for, and the sicko's who sit and dream up problems are an active group.