To Eliminate the *mouse* from the problem domain, use the context menu key next to (on the right of) the Right hand "windows" key on your keyboard to bring up the Right Click menu insteaqd of Right Click on the mouse.
If you keyboard has no contect menu or Windows keys on it, or you are unsure which key I mean - then use the Shift-F10 key sequence to bring up the Right Click (aka context) menu.

I expect as everyone else here says, that one or more of your "shell extensions" (i.e. Explorer add-ins) is causing the problem here.

The other point, is that you say "1 in 3" of your right clicks provokes to problem.
What is in common with the folders/files you are right clicking on when it does happen - that may provide a clue as to which shell extensions to start fingering.