The programme is available in the US,
This isn't the first time Microsoft has attempted to persuade users with discounts. The company has offered up to $650 (£420) off the Surface Pro 3 in exchange for a MacBook Air, $100 (£64) off the Xbox One for PS3 owners, and $200 (£130) off a Surface tablet when exchanged with an iPad.
Whether the tactic works is still up for debate. Windows 10 is on over 110 million PCs at present but Microsoft's stated aim is to get to over one billion so there is still some way to go.