There has been a problem in 20.x releases (don't remember exactly the versions) that a process is taking 100% CPU (on a single core) if a folder is missing.
Make sure the folder "%Userprofile%\Videos\Radeon ReLive" exists or upgrade to the latest driver (as it's resolved in later versions after 20.12.x I believe.
Give it a try or check if the folder is missing.