PC personal computer. But really it does refer to a windows base device. But i'm using it as a general machine.
See, when I was growing up the term was OS agnostic. It really meant a computer that could do all of the processes without the need to be connected to a mainframe (I would argue that we are going back to that type of computing just in a slightly different way). It was really only when Apple was marketing itself as different then Windows that it has slowly meant Windows machines, but I digress.
You can get viruses on mac or linux. not as common vs windows but it happens.
A lot of stuff now is being OS agnostic. Couple of yrs ago PDF reading in web browsers was used as a vector for virus on OSs. Now you have scripts embedded in doc files that are served as vectors for any OS that can read those files.
That landscaping is changing and part of the problem is that those using some UNIX like system (Linux, Mac etc) are being complacent.
Windows as always done things out of convenience for the user, that I would argue is bad and keeps them easier to be susceptible for compromise though. That and the sheer user base amount, Windows machines will probably be a big target for a long time to come.
I do believe computers should be updated, if you need to use legacy programs that can't run on newer machines, run VMs and isolate them. The one thing that I don't like about updates, particularly with how MS does them, is that the come with unnecessary fluff (that would include ads, but ironically I do believe Jobs had his name on a patent to embed ads in an OS, but never put it into action).
One thing that I do think is just as important as updates, is educating the user base. It seems to me that most computer users, use computers just as tools to do a job, nothing more. So there is no desire to learn anything more then what just gets the job done. No matter how up to date a rig is, that's not going to help with the human element.
Just like the mere fact of having an anti-virus program isn't going to be the end all be all protection.
I think that there is a false sense of security (oh the irony) for users that think just doing those 2 things is enough.
Keep in mind to, other devices are starting to be attacked on a network and not just the traditional attacks on desktop, laptop computers. Routers being a big one. Something that doesn't keep updated (if at all) often and most people don't even think about it. No matter how protected your computer is, if they can get your router, they can still do things. May not be as severe, but they can still have "fun".