Howtogeek posted How to Use Your Free Windows 10 License After Changing Your PC's Hardware
A quote from the article:
The free Windows 10 license you receive is tied to your PCs hardware. Youre still allowed to use Windows 10 on that same PC even after changing its hardware, but that may not be clear. Microsoft wont give you a product key.How to Use Your Free Windows 10 License After Changing Your PC's Hardware @ Howtogeek