No, you don't have to turn off Windows 10 before getting a new PC.
No, you don't have to turn off Windows 10 before getting a new PC.
This method seems to let you switch your retail Windows 10 version on your new PC. Deactivating the key should keep your PC functioning normally until you change it again. The key will likely be stored in your Microsoft account, so you can view it there or manually record it if needed.
Windows shortcuts and activation are turning into a big party. Just use your Microsoft account to get through!
Just set it up on your new PC and you're good to start. A phone activation could be required, but it should function. The other system license will be disabled. Avoid turning on the connected online PC; you'll need a fresh Windows license for that machine or switch to a Linux distribution if you wish to continue using it.