Simplest thing you could immediately try:
Download newest spacedesk Driver version Beta RC v1.0.50
Install the v1.0.50 msi
Uninstall v1.0.50 msi again.
Cleanup routine should remove all leftovers of v1.0.50 and all older versions.
The hard way:
Goto instruction manual https://www.spacedesk.net/user-manual/
Goto chapter “UNINSTALL ON WINDOWS PRIMARY MACHINE” => “Manual Uninstall (Troubleshooting Only)”
Do all 7 steps (Step 1 – Step 7) mentioned in this chapter
Chapter “APPENDIX”=> “File List” states all executable files. After deleting all these, there should be nothing left to see any more.
If anything is coming back, then please also check which ones of the files stated underneath Chapter “APPENDIX”=> “File List” are coming back.