The option to activate or deactivate dedicated GPU in BIOS may not be available if your CPU doesn't have any integrated GPU on board my question is what type of CPU are you using are you sure it has integrated GPU cos not all CPU has integrated GPU you have to figure that out first
I do have a gpu on board "Intel(R) HD Graphics" and it works when i unplug dedicated gpu but can't make them work together maybe it's bios limitation can't enable options in bios and my motherboard is Gateway Dt71 already try their new bios version of 2012 -__-.
My cpu is i7 2600
I don't know what is going on here but I can see that it's your motherboard issue because I have a motherboard here and the BIOS has no settings to activate or deactivate igpu or even graphics card but still whenever I connect my HDMI cable direct to the motherboard I always get a display even when my graphics card is connected
Yeah Furryball it depend on the motherboard, some allow the integrated gpu to work aswell as dedicated one same time, not the case for me unfortunatly