I don't normally spend my time worrying about the monopolistic practices of that software company, but this case is too bizarre to go unremarked. In a nutshell, at this site Microsoft explain that if a computer is donated to a school, it's a legal requirement that the original software installed on the computer be donated with it. Notice that they agree that the school can upgrade the software on the computer to another version of Windows. Why, then, should the school not accept computers which have been previously upgraded with another operating system? When is an upgrade allowed, and when is it not?
[Thanks to Rory for the pointer.]