Ihave a custom bult desktop computer at home. A few months ago it stopped sending a signal to the monitor when I turn it on. The tower turns on but nothing shows up on the screen. If it does start then it freezes almost right away. i took it in to get viruses cleaned off of it and it did solve the problem for a few weeks. it started doing the same thing about a week ago. A guy at best buy told me i needed to update my graphics card via flash drive...but how can i upload a flash drive if there is nothing on the screen? I have a NVIDIA Geforce 9600 GT card now. Another guy at our comp help at school said my card was just dying and I needed a new one. I just got a new one at best buy (XFX ATI Radeon 1gb ddr2) IT STILL WONT WORK! Please help me out!