How to find out the product key from Win 8 on a laptop?

Question

Windows

There is Asus with Windows 8 single language, hhd of which is heavily polluted. I want to demolish everything and re-partition in GPT. There will be several systems.
Only the last five characters are visible from the key. How to know the rest? And where can I download this version of Windows 8 single language?
UPD: I learned the key using AIDA64 It
remains to find out where you can download Windows 8 single language?

Answer 1

Do license stickers on the bottom of laptops no longer stick?

Answer 2

There is something about this, I didn’t dig deeper, I decided to be content with restoring from the image.