Please need help with pci video card installation

Hi all
im new to all this so dont expect me to know much about vid cards
Well, heres my problem
I just got a visiontek xtasy 9100 pci card. I tried to install it but all i get is a black screen. I read other post on other forums saying to disable onboard graphics, which i also did through the device manager. I tried both uninstalling and just disabling but nothing worked. I tried switching to other pci slots, that didnt work either. Then i accessed my bios, but it doesnt provide me with any options on disabling pci or vga/onboard graphics.
The only thing that may be important in bios is the advanced tab, which branches of to pci devices, bus options, and device options. Pci devices- there is the vga controller, but can only switch between IRQ 3,5,11, no idea what that is.
Im running a pentium 3, intel 810 chip motherboard, 192mb of ram, windows xp professional.
Please help me fix this problem.
Thnx a lot in advance

I already did that too, im kinda hopeless right now

Ok, its a compaq presario 5000 series, i belive the model number is 5bw250 with 700mhz, not quite sure who manufactured the mobo but i can imagine it was intel.
Thnx for the help so far