Hi I just got my HD 3870 GDDR4 512MB Memory. My Power Supply is new to 700 watts install just fine. Anyways my old card is DDR2 512MB ATI Radeon x 1600 Pro. Which is running fine. When I turn off the power to the computer always do that first. I took out my old videocard the small videocard. Then I took out my big huge videocard lucky it burly fits in my tower pc. I install to the PCI-E x16 bus slot which my old one had x16 bus slot. The Card took almost two slots huge! Anyways I plug my moniter back in into the VGA port turn on moniter first then the PC anyways install failed no display was found no BIOS first screen etc showed. Anyways what did I did wrong? PC is not even 2 years old. Its not really HD PC but it has a PCI-E slot plus it fits in fine I have Vista on it to. And I have HP w22 screen LCD. Anyone can help me thanks?! So I instert my old card that work find can't get my HD card to work. Thats what I get buying a Visiontek product. Other card was only made by ATI before it was name Visiontek.