do you have a on board video chip on the m/b if you do
reseat the card
then
boot from the onboard
in the device manager disable the onboard
if the card is listed uninstall it
turn the computer off
install the card
change the video cable from the onboard to the card
reboot into the bios
check to see if you can disable the onboard in there and set it to detect agp or pcie first
save and exit the bios tapping f8 and choose vga mode
when windows finishes booting
disable a/virus
install your drivers for the card
reboot the computer
what are you running
video card
cpu
m/board
ram
power supply
brand
wattage
check the listings in the bios for voltages and temperatures and post them
reseat the card
then
boot from the onboard
in the device manager disable the onboard
if the card is listed uninstall it
turn the computer off
install the card
change the video cable from the onboard to the card
reboot into the bios
check to see if you can disable the onboard in there and set it to detect agp or pcie first
save and exit the bios tapping f8 and choose vga mode
when windows finishes booting
disable a/virus
install your drivers for the card
reboot the computer
what are you running
video card
cpu
m/board
ram
power supply
brand
wattage
check the listings in the bios for voltages and temperatures and post them