Beware of software sellers bearing free gifts. MS software (not just their OS) supplied by universities has to be uninstalled before the equipment can be taken home, under the terms of the licence the universities buy into. When the users accept the software, they are deemed to have agreed to these terms.

For completeness, Apple OS software licensing is downright weird. Every now and then, one or two departing postgrads would ask whether they could buy "their" computers. But before Apple hardware can be sold on, the software on it has to be restored to the exact condition it was when it was delivered. No third-party software, no OS-version updates, no security updates of the base OS: an OS that's three to four years out of date. When we (the Physics Dept) then explained that the hardware would also be three to four years old, and that much nearer to failure, we found the uptake from postgrads went right down.