As I understand it, some makes of PC come with software for making a backup of Windows which is legal.
Howeverr, I think that this is rediculous and I, like you, would not dream of buying a PC that did not come with at least a recovery disk and preferably a full Windows CD.
The Medion laptop that my daughter got a couple of years ago came with a Windows CD as did my recently purchased Aries from Savastore. But be aware that whilst I am delighted with my Savastore purchase there are lots of disgruntled customers who have posted in Consumerwatch.
If I were you I would shop around to find a PC that comes with a disk. Good luck.