I just found this system because during comrades have such PCs and can not install Linux. This principle (which dates from 2005 apparently) that the BIOS and the hard drive of the PC have a common identifier. Therefore it is impossible for the owner:

installing a second operating system on their computer even if there is another version of windows (multiboot);
to launch a Live CD or System Restore CD (like Ghost);
to change the original disk (tattooed) with another hard drive (not tattooed).

It is simply amazing that such machines have been put up for sale! I hope it is no longer done.