What a nightmare! I had those ogg files that happened to use names with strange characters and Windows Explorer refused to rename them! When I entered a new name, Windows Explorer stopped working as if in a loop, trying forever without success.

I could wait for hours to see if a message was going to appear or anything, but after a few minutes I realized that perhaps I should find some other solution.

I tried even to delete the whole folder, but Explorer still refused to accept any action.

The only solution that worked was to use Flexible Renamer to rename the problematic files. Just make sure you restart Windows first. Enjoy!