If you agree to the EULA, then you can't get a refund for the Windows license that comes with the computer.
Given your actual intent is to get the keyboard working enough to boot from CD (or whatever), not to agree to the agreement, and you didn't actually avail yourself of any of the benefits of the software, any retailer on the other side would have a hard time winning any class action lawsuit.
Among other things, assent must be meaningful
Any attempt to 'tie' the hardware to a proprietary OS can be met with a legal challenge on these grounds. So, regardless of what manufacturers would like customers to think, it is possible to obtain an OS-free computer, even if it entails refusing an EULA and getting a refund for the unused OS.
Many people think this argument applies to Apple, too. But that's a mistake: Apple computers are not marketed as 'PCs'; and their computing system, from hardware to OS, is Apple throughout.
Microsoft works with PC manufacturers to pull off this anti-competitive hoodwink on an ignorant computing public. If it were tested properly in court, the whole corrupt practice would be torn to pieces.
You can claim it's an "anti-competitive hoodwink" but Microsoft just spent a decade with the US Justice Department's foot on its neck, specifically to prevent any anti-competitive hoodwinking.
There's also nothing to prevent PC manufacturers shipping whatever they like. Many if not most now sell Android tablets, some sell Chromebooks, the server suppliers support Linux, and so on. Some sell Linux on PCs, including Dell and Asus.
The idea that the market failure of Linux is down to some sort of evil conspiracy might make you feel better but it doesn't square with the facts.
Furthermore, the fact is that if I want a particular laptop PC, Windows is bundled in almost every instance, and I have to jump through hoops to force the manufacturer to take it back.
It's not a conspiracy. But it is illegal.
Also, these are integrated packages so the idea that the OEM should take Windows back is illogical and nonsensical. It is a delusion that bears no relation to reality.
If you want a comforting thought, price is largely a function of volume, so you are getting massive benefits by riding on the back of the economies of scale created specifically by and for Windows. You are gaining far more in real cash savings than the trivial amount that you pay the OEM for its version of Windows.
In the long term, however, you should try to see this for what it is: a very pragmatic business. It's not religion.
It was annoying. Reading the headline, it appears that a similar annoyance is continuing even now.
Either way, dealing with unprofitable customers is a losing strategy for any business.