I can only tell you how it is in Japan, North America and Europe, the only parts of the world I have lived.
Unless you go for second hand computers, finding OS free computer is like finding a proverbial needle in the haystack.
At least here in France, there is a regulation making it mandatory for manufacturers to offer a "deinstallation" service after sales. I took an advantage of this system, sent Acer laptop to the service centre and got a Windows "deinstallation" certificate along with a 30 Euro check
The cost of shipping is also assumed by the manufacturer... Poor Acer. I think they made almost no profit selling me this rock-bottom price Aspire (which I later flashed with a mod-BIOS and swapped parts to convert it to their top of the line Aspire, but that is another story).
The reason behind this French system: there has been a precedent where someone has successfully sued a manufacturer for forced sales of Windows and got quite a substantial money in return.
Vive la France