Please help,

I want to upgrade the video card on this computer.Aptiva 2153 E2U

On it now is the ATI rage pro turbo agp 2x 4 mb onboard chip.

I have one open PCI slot in the computer.

I bought a Xtasy Radeon 9100 64 MB PCI card ,

The problem is that I cannot install the card....

Let me tell you what am I doing:

1- going to system , device manager , display adapter,

I've tried different thing there like clearing the checkbox for "exist in
all hardware profile" I also tried to remove the rage pro in device manager,
I also tried both at the same time with no success.

2- When I install the new card in the PCI slot the computer refuse to boot.

What am I doing wrong ???????
Thanks
Richard