“It’s not showing the world just the HUD.”
TGA files can have an Alpha Layer (a plus layer to the normal red, green and blue layers) that shows what is visible and what is transparent in the other layers. Alpha Layers are Black and white, black mean the image will be transparent, white mean it will be not transparent.
The Quake Wars screenshot alpha layer is making only the hud to show up, it’s white on the hud, and black on the rest. You need a software that can ignore the alpha layer or you need to edit the alpha layer in a image edition software and make it completely white.
The progran Irfanview (to view and edit images) have an option named “[x] Show TGA/DDS alpha/transparet color” on Option/Properties and Settings/Viewing. If you turn it off “[ ]” it will ignore TGA alpha layers and the image will show properly.