new category ideas
I realize you don't want to have a long scrolling list of categories and have to limit when you ad new ones.
I would say that adware/spyware is and will continue to be as important as virus threats ever was, and is probably to the point where it deserves a heading. (What do you know, it would even out the lists!)
Another more random thought, Sub categories, if you select something like Windows, maybe allow to select which flavor of Windows you are working with? The same could be easily be said for Servers.