Thanks for the reply but I want to limit my search to the more established antivirus software out there like Kaspersky, Nod32, bitdefender, etc. Doesn't have to be free. I just want the option to update the antivirus definitions without internet connection. I think Bitdefender used to have that option in which you can download a weekly definition, save it on a usb flash drive and update from the saved file. Does it still do that? Are there any other antivirus that does that?