You may use avast! for DOS (http://files.avast.com/files/eng/avast77e.zip).
Updates here: http://files.avast.com/files/latest/lguard.zip
The Registration key you will find here: http://forum.avast.com/index.php?board=1;action=display;threadid=1509;start=0 at section avast!
You can burn a CD with this. You can use F-Prot for DOS too.
But better if you buy BART CD for that task.