so i want to do a fresh install of windows on my GF’s computer but the computer never came with a recovery cd or anything like that so i told her that i would need a windows cd to do it. he dad knows this guy that he can get the windows cd for free but he said that he has to know what version. so i wanted to upgrade the computer from home to pro but the guy said that you cant just throw any windows version on the computer?!?! now it was my assumption that if you reformat a hard drive you can install anything you want on there but the guy insists that you cant you can only put on what the sticker on the side of the case says.
am i wrong or does this guy not know anything