So I had a previous computer that I bought prebuilt and that had a licensed version of windows preinstalled and activated with it. Several months ago I built my own computer and installed windows but didn't transfer the product key. I put the hard drive from my old PC into my new PC for extra space and for old pictures/videos, etc. I was wondering is it possible to receive the product key from the hard drive (which does not contain the boot for the computer, the boot is on an SSD) without having to take it back out and put it back into the other PC and obtain the product key that way. Thank you to anyone who reads this and is willing to help.