So I have been seeing these Windows OS software title ending with something called OEM on website such as Newegg. Can somebody please explain me the difference between a OEM OS and a normal licensed OS, other than the fact that the OEM is cheap? Also why is it cheap? Thanks. First post on Tom's Hardware! Also I am in a process of building my own gaming PC. Can someone please direct me to a sub-forum where I can get feedback on my PC parts, and their compatibility with each other? Thanks again. Have a Merry Christmas!