Hi gals/guys

I have purchased a new Graphics card (GeForce 5200 PCI card the one with 128 MB memory), the reason for purchasing the card is my brother wants to play some 3D games...... Now let me first tell you about the BOX in which i have installed this card.

Its 3.0 GHz Intel Processor with 1 MB Cache (HT Technology)
Intel 915 GVLG M/B
256 DDR
LAN/VGA/Sound card (Built-in)

Now I deleted the builtin VGA driver and restarted computer and then I put the external graphics card in it, when I insert the CD (Auto-run) of that graphics card it gives me error message "No GeForce Card found" ..... I thought may be the driver is outdated... so i manually browse the CD and installed the driver........

Rather than getting better graphics result i got worst result then before...... even games which were running perfectly alright eariler were not working properly...... When i Run DirectX diagnose i could see that the AGP Texture was disable which used to be exactly like this before ...... Even in the GeForce properties i could see the OPEN GL option but it was grey (Couldn't change it settings).

I went to the website, downloaded the latest driver of the card, plus i downloaded the chipset driver of my board too. Now when i remove the previous driver and updated with the latest one i could see the AGP texture enable and running the test things were working alright...... But now the OPEN GL tab from the properties of the card is gone...... And games again worse..... Most of the games which were working alright on builtin VGA are not even working on this card....... I have too the Online support but problem still not rectified.......

I have checked from the setup (BIOS) for display external PCI card is selected........ Now it would be pleased to to know what is wrong with this card? Is it not compatible with my M/B? I am really upset after getting this Card...... and i really need help.......