Intel LGA1155 DDR3 1600 ATX BOXDH77KC
Corsair Vengeance Blue 16 GB DDR3 SDRAM Dual Channel Memory Kit CMZ16GX3M4A1600C9B
Intel i7-3370 Quad-Core Processor 3.4 GHz 4 Core LGA 1155 BX80637I73770
GeForce GTX 550 Ti
Corsair Enthusiast Series 650-Watt 80 Plus Bronze Certified Power Supply
Western Digital Caviar Blue 500 GB SATA III 7200 RPM 16 MB Cache
Windows 7 Home Premium SP1 64bit
Samsung SH-222BB/BEBE 22X SATA DVDRW Drive
Antec 9 Hundred Black Steel ATX Mid Tower Computer Case

I have a Samsung 32 inch HDTV I like to use as a monitor. When I plug in the hdmi cable directly into the motherboard, I can see the video without a problem. When I try to download the video card's driver however, both with the cd, and trying manual installation, I get the error "The graphics driver could not find compatable graphics hardware." I opened up my pc and realize that the video card is not getting power from the 6-unit pci connection to the power supply. After plugging that into the video card, and making sure the video card is well in place, I try starting up the computer. The computer starts, but I do not get any video when I plug it into the motherboard, or the video card. When I remove the power to the video card via the pci cable, I can see video using the hdmi cable, but only when it is connected to the motherboard. Please help me, why is it that I cannot see anything when the video card is powered by the pci cable?

reseat your card ... and go in bios select GPU at pcie , save , boot and then plug cable to your card

Do you have been check it your driver version and compatibility?