I have a Compaq Deskpro EN PII 400 into which I am installing a GEForce MX4000 (PCI). I have tried the following:

1. Plugging it in along with the old card - the system doesn't boot
2. Taking out the old card - the system doesn't boot
3. Disabling the ATI card in the BIOS and enabling PCI serching for VGA - the system doesn't boot
3. Upgrading the BIOS - still No Joy

Does anyone have any experience of this? If so, please help!