When you double click any .scr file it opens Notepad, instead of starting such screen saver. This means some software (usually AutoCAD) changed default file association for .scr extension.

You would need to restore .scr file association by following the instructions:
https://knowledge.autodesk.com/support/autocad/learn-explore/caas/sfdcarticles/sfdcarticles/How-to-change-SCR-file-association-in-Windows-after-installing-AutoCAD.html

Alternative instructions:
https://www.sevenforums.com/tutorials/19449-default-file-type-associations-restore.html