The disks are licensed and given away for “free” (with your new PC)… that does not mean the contents of them are free to do with as you please. It would be like taking books from the library (given to you freely, if temporarily) and making copies to distribute.
So, is that to the point of putting someone in prison?
Well it was theft, plain and simple. What is the point of having possessions if there are no laws against stealing them?
If he didn’t want to become a criminal, he should have approached Microsoft to see under what terms they might have allowed him to do what he did, if any.