Hello, I have an Intel D915GAG Motherboard, just installed an ATI 5450 HD graphics card, there is no video output from the card or onboard VGA port, but when I remove the card the onboard VGA port works again, please could someone help me, Thank You.
THere should be "priority" settings in BIOS. It seems it is set for extrenal graphiocs card to be main. Try switch those settings so internal graphics port would be main.
It depend on your mother board Bios option. e.g a typical ASUS motherboard the "PCIE->PCI->IGP" option is the one that disables the onboard, this option means if it detects a PCIe or PCI GPU it will disable the onboard GPU, "IGP->PCI->PCIE" this option will keep the onboard GPU enabled even if there are other GPU's in the system