Maybe I'm just midreading, but it sounds like you're trying to take out the IGP from "in" the motherboard... to make an IGP work... which doesn't make sense.
Normally, when you use discreet graphics (i.e. an actual graphics card), the integrated graphics of the motherboard gets disabled to save energy and prevent I/O conflicts. If you take out the discreet graphics, the computer should automatically switch back to the integrated graphics when booting up, unless it's specifically disabled in the BIOS settings (a setting that's only useful if you're constantly switching graphics cards, e.g. for benchmarking purposes).
This way of automatically switching graphics is useful because if something happens to the graphics card, and the IGP still works, it helps you identify exactly where the problem is.
