I bought the CD bc I only used it on my laptop; I also got a virus but I emailed Schweser Support & told them the situation and they reset my username/pwd so I could reinstall it again, which was very nice of them!
I agree, if you plan on using multiple computers, then go for the online option.. If you're going to use just one personal computer, get the cd. I heard pple had problems with getting online Schweser.. I had no problems with the cd version.