Nobody's being forced to buy anything they don't want. A guy voluntarily purchased a laptop with Windows installed on it, and wanted to return part of what he bought.
Actually what he bought was a laptop with a refundable copy of windows. If - after the sale - the vendor is claiming that what he bought is something different, i.e. a laptop with a non-refundable copy of windows, then it is the vendor that is in the wrong.
It's not about forcing or not forcing people to buy something they don't want, but requiring vendors to be honest on what they sell, and if they sell an item which has conditions, they are not allowed to unilaterally change those conditions to the detriment of the buyer after the event, especially if the buyer relied on those conditions before making the purchase.