Extra WP installations

I recently moved my websites to a new host. It took me a while to get everything back up and working. I think in the process there were two installs of wp 3.1.3 and 3.1.1 in folders named wordpress and wordpressbk. Neither one seems to have any content in them as all my content is in the wordpress install that resides below these two folders.
Do I need or want to keep those folders intact or can they be deleted without any consequences?