....

I've heard about those locked boot loaders.  One should avoid buying such devices, but I think it must be possible to hack them open.  I don't think there is any legal procedure that can be used against you for REMOVING software or firmware from a device ; and if so, it would be the OEM that would have a strange hardware selling licence.  I've never had an intel machine on which I couldn't remove windows entirely (that's usually the first thing I do with a new computer).  It is true that UEFI is a pain, but I thought even (though I never bothered) that there are laws in some countries that force microsoft to pay back the windows license if you ask to remove it.

There could be manufacturers that lock down windows in the UEFI.  Then one mustn't buy stuff from them.  They can make life technically difficult, but I don't see how you could be legally annoyed by doing away with software.