After Win Update installed the Intel driver for the Intel 915GM/GMS, 910GML Express Chipset, I have observed some weird behaviour. When I do NOT have applied external power, the monitor/display turns yellow-white and looks like it only is able to display 3-4 colors. When I apply external power, everything goes back to OK. This even happens if the computer is on and I remove and apply external power.
I've posted this on the Windows 7 - Microsoft TechNet as well