Well before you even make the server, I would make sure you have enough bandwidth... For an 10 man server you will want 2500 kilobits/s which means 250 kilobyte/s. For Source games you need ~25 kilobytes/s per client. So hardware is not the biggest issue in most cases. To make one in windows you have to download the steam dedicated server client... So you need HLDS, I'm not sure if they still make it standalone...