I'm running XP Home Edition with McAfee protection. I had 19 versions of Downloader, and 2 versions of Backdoor viruses. They didn't come through e-mail. They came through a web site, or a program from a website that I may have clicked on. The sad part, I bought McAfee for just that reason, to catch viruses, but it didn't catch any of them and when I ran McAfee scan it kept telling me I didn't have a virus. I know I ran it a half dozen times. Trend Micro said I didn't have any. AVG cleaned most of them but by that time, the damage had been done. They are not true viruses so I don't understand how they done that much damage. I had to run my recovery disk through and start again. It took 5 tries to get them to run. The first one kept stopping at 42% telling me it couldn't read some file. On the 5th try it went on through. Oh well, such is life.