[dpark]

There's a rather large difference between contractually forbidding PC OEMs from selling Windows machines bundled with BeOS and technologically blocking non-Windows OSes from executing. It's one thing to say "you can't bundle another OS with mine". It's another thing entirely to say "your hardware can never run any OS except mine".

[beagle3]

There's actually a very small difference.

They both result from signing an agreement between said parties, and basically provide the same benefits to both parties (given that most people won't install an operating system themselves).

Except one leaves a choice to the end user, and the other doesn't.