Bob, I have installed two as a precaution. One runs separately in my mail program and I have mcafee which looks at all files. I had this idea based on information I receive weekly in Ken Dunham's Infection Connection . He suggested having a backup downloaded Bob. I will give you the address of the site so you can have some idea of why it was my choice. http://antivirus.about.com/compute/antivirus/mpremail.htm He maintains that if you are serious, or in need of a second opinion, have two as one product does not do it all. Also, as a matter of interest, he mentions trojan horses and other malicious viruses that are unique to macs and ones that pcs and mac products share ... I hope I have seen the last virus for a while Bob... *Seattle* audrey whose pwp friend refuses to be on the list due to virus problems...:)