Look at the specs of your chosen pad. If it doesn't say it works with whatever version of windows you have then there's your answer. And please don't go thinking it will work even though its not listed because it won't. It's not listed for a reason. It would be a big selling point if it was so if they left it off it was for a good reason.
And to answer the other question. It typically comes down to drivers; without drivers to interface with the OS, nothing would work.