I downloaded 12.04LTS and install it alongside with windows. After I installed my graphic card on my Unit,everytime its boot in Ubuntu then a sudden blackscreen will happen. I try to connect my Monitor on my On board graphic on my Motherboard and it's running fine;I hurriedly download the graphic driver for my HD6790 and it have a extension of a .run file. Unfortunately I can't install it because it will ask for the graphic card to be installed first before I install the graphic driver... How do I install my graphic driver ? PLease Help, Want to save more bucks.