Graphics Card installment problem! HELP!!

[This Toast]

So I'm trying to install my 9500 gt to This Cactus' PC since I got a Radeon HD 5550.
>Installed it on the motherboard
>PC turned on
>Detects the new device and "Installs new driver software"
>While it was installing, the PC rebooted
>Once it's on, I don't see the "detecting" process/program
>Nor can I find a trace of the name "nVidia GeForce 9500 gt" anywhere on Device Manager

1. Manually download driver
>Downloaded some bunch of drivers
>Always saying they could not find it

2. Reconnecting the Card to the slot
>Nothing happens
>Still same

Additional Info:

Spoiler (click to show/hide)

-Works perfectly on MY PC
-Power Supply is 500watt
-2gb ram

Is there something in device manager that I should un-install so that when I reboot, It installs again?

[This Toast]

Still asking help.

[» Magic «]

is it in properly?
is it powered properly?
uninstall all previous nvidia/ati drivers, reboot, then install nvidia

[Goat]

could it be your lack of RAM? you would think you would need at least 4gbs.
my gtx 460 has 2 pci ports in that back, does yours need it?

[This Toast]

Powered properly.
Monitor cable connected properly.
Motherboard is asus p5rd1-vm motherboard.
There is a chipset display adapter built-in called ATI XPRESS 200
>Uninstalled it then a buggy display.
>Shut it down
>put in the 9500 gt
>turn on
>windows load for 5 mins
Nothing.
Just a 800x600 reso on a 1024x728 monitor.