The problem is the software is considered as much a part of the package as the hardware. You don't buy a computer from Dell without a processor, so why should you be "competent" to install a processor or indeed an operating system.
I also seem to remember M$ threatening OEMs a few months ago about shipping a PC without an OS, they called it an illegal machine and wanted all OEMs to report it too them immediately, with this kind of thing is it any wander OEMs wont refund anything on the OS.
Unfortunately this is the way it is. I recommend buying a machine with Windows 98 rather than 2k/XP that way you can either give the license to a local school (although this too is deemed illegal by MS as they have decided that an OEM licence is bound to hardware, go one prove it! :o) ) or similar.
Any way, that's the way I see it.
Regards,
Michael
P.S I don't think I can make the 3rd.