I have a Acer Aspire T690 MMX 1 desktop PC. I have been trying to to install a Radeon HD 5670 1GB DDR3 Video Card. The PC boots but no graphic are displayed to the monitor. I have replaced the Power supply to a 450W to allow for the requirements of the card but nothing is displayed. \nWhat else could it be. do I need to update the BIOS. does the motherboard support a 1GB card?\n\nRunning windows Vista Basic.