SureAI

I am about 40% through the game (I recently finished the quest at the old man's villa.) Enderal has suddenly stopped recognizing the "r" key, so I can't fight anything. I went back to an autosave, and started a new game and the same thing happened, so I don't think it is a corrupted save file. Should I next try deleting and reinstalling the whole game? If so, do I need to do anything to preserve my saves?

I just want to add that this is a great game, particularly considering the price, and I would have just given up on it if I weren't having so much fun playing it. Thanks for the immense effort it must have taken to create it.

That's strange.
Check your keyboard controls in the menu.

You could upload a savegame. So we can test if it's corrupted.
Savegames can be found here: documents\mygames\skyrim\saves
A savegame consists of two files: one .skse and one .ess (please zip them together)
Thanks.

I started a new game, as I said, and the same thing happened, so it is not a corrupted savegame. I certainly did check the keyboard commands, and the R key was selected to draw weapons, so it is not that either. I am guessing that the next thing to do is to uninstall and reinstall the game- I just would like to make sure that I won't lose my save.

You could try to remove the C:\program files(x86)\Steam\steamapps\common\Skyrim\Data\Interface\controls\pc\controlmap.txt
It should be generated automatically.Every contol will be reset to standard controls.
If that doesn't help I would recommend a reinstall.