My computer was pre-installed by Dell with Windows 8. I upgraded to 8.1. I have a USB drive from Dell with Windows 8. I clicked "Add Features to Windows 8.1" in control panel, but it asks for my product key. How do I find out my current product key?
I tried this answer https://superuser.com/a/952806/130929
And got a key
But it didn't work in Control Panel