Theres a bit more to that story, leading up to Vista Intel's iGPUs lacked proper DX 9 support, just partial. Particularly 910/915 were marketed as "Vista Capable" but not "Vista Premium Ready".

And the later ones which did have full DX 9 support really weren't that much better. I recall drivers being an absolute mess for a lot of external peripherals too, many that weren't even dated took ages to get something usable for vista if at all.