I messed up Windows 10 - - - what now ?

It started with me trying to make room on Disk C to download AMD software. I copied and pasted ProgramFiles to another disk to make room temporarily. That didn't seem to go well. Permission asked, denied. A big mess.

After a restart, I got a black screen for a while and then went to desktop.
Right clicking on Disk C makes the blue circle appear and nothing opens. Clicking on windows bottom left does not open the menu. and everything seems to run slower when trying to browse files.

I have no backup because I didnt expect such complications.
When I try to delete the Program Files in C, it says I need permission from SYSTEM, but again, right clicking to go into the settings doesn't work.