That’s my solution! I needed t change the engine to Cycles.
-Can I do this without changing away from the Blender
default renderer?
What is the default renderer called, and like, anyway?
While using Cycles your chances of not using “noodles” are slim ;).
All Cycles materials are different from Blender’s default Blender Render engine ( often called BI, Blender internal).
There is no “Window” projection for the World while using BI. Closest is View which applies spherical distortion to flat image. You need to use pre-distorted - equirectangular one and set this projection on Texture tab for World Mapping. Background can be seen normally through Camera - don’t be surprised by variety of color lines if you are not in Camera view (zero key on Numpad).
Use “Import images as planes” addon and scale rotate and place background plane in Camera view - that’s easiest using BI. Map or paint panorama image (Shadeless material, you can check on Toolshelf while importing) on huge Cylinder or half Sphere if you need surround view. Parent this object to the Camera to imitate it being ‘real’.