How to apply a standard jpg texture.

Hi

Since I upgraded to Unity 5, the software automatically generates a new “glossy” texture whenever I apply a standard texture to a standard cube or sphere (created within unity)

So to explain further, if I go to GameObject > 3D Object > Cube

then drag and drop a .jpg material of sand onto said cube, Unity creates a new texture of the sand with a variety of controls such as “metallic” and “glossy”. It applies that instead of the standard texture.

Any help would be appreciated.

What do you mean by a “standard texture”? You mean a material with an albedo and nothing else?
Then change the shader assigned to the material to “Unlit > Texture”.