I have a Vostro 460 Win 7 64bit. Has been working great with two monitors off the ATI Radeon HD 5450 card which came pre-built. I've just acquired another flatscreen monitor and I think that I should be able to run this from the on-board video card, According to the spec there should be an Intel HD 2000 built into the mother board (and there is certainly a physical port present) but it doesn't show up in device manager).
I've been into the BIOS and ensured that the video detect is set to "Auto".
Any ideas or suggestions as to why the integrated card doesn't even show up (and what I might do to fix it?)