If you’d like to do this, you’ll need to shut down the broken computer, open it up, and remove its internal drive. You just need to remove the drive, connect it to a functional computer, and point ProduKey at it. If you have a computer that won’t boot, you can recover its keys as long as the hard drive still works. It’s that easy! How to Recover Keys From a Separate Hard Drive

Write down any product keys you want to keep and store them in a safe place.