While most of the people who have responded here are mostly right, there is one thing people are neglecting. Yes, it is true that a Windows virus cannot do much, if any, damage to a Linux install. However, these virii can still run if you execute it through Wine. There's no harm in it, though, since Wine is just a Windows emulator, I just thought it should be addressed that there is an exception to the "exe files can't be run on Linux".