Somehow my file association got screwed up. Whenever I try to open a .blend file (for Blender), it opens photoshop. I try to change the default program it opens by clicking Change on Open With, then I go and select blender, but it doesn't show up on the list, and refuses to let me set Blender for the default program. Via google I found an answer that involved going into regedit, finding HKEY_CLASSES_ROOT\Applications\(Application name)\shell\open\command and changing it to the correct directory. It's already in the correct directory, so that doesn't help. Can someone please help me?