AMD HD Radeon 7800 Missing graphics card

i booted up my computer and it is nowhere to be seen at all. its like it uninstalled itself. i tried finding drivers and updates for it but i get this.

 

its not in device manager its not in bios...so i ran a clean uninstaller tool. im guessing i need to original files to install it but it already came installed on my pc and the program when i run the amd 7 series off the cd is crashing..