Can't change file or folder names on the desktop

I added a new folder to the desktop of my hubby iMac and found that it wouldn't let me change the name of " untitled folder". I have never run into this before and my iMac is working fine, so hubby might have clicked on something he shouldn't have, but I can't figure it out. So I thought I would ask here. It would let me change the name if I went into get info, but if I just clicked on the folder name, like I normally do, it just opens a window. Help please! And thanks.