Please check the past postings before posting your request. Had you done so you would have found this thread, with a list of a couple free anti-virus apps. Then instead of waiting for a reply, you would downloading apps!
Scroll down and you will see a listing I had posted with Anti-Virus progams
http://www.oldversion.com/talk/index.php?a...t=ST&f=2&t=1236
there is also more free ones elsewhere on the board, look for similar topics to your request and skim through them.