Windows 7 - Intel 915g Video Driver in Compatibility Mode

Short version: I cannot get the Intel 915g XPDM driver to install, even in compatibility mode.
Background information is below to help spot any possibe problems.
Read it at your own time and risk.
Everything I know comes from the Microsoft website, or from other forums and blogs, so feel free to correct me on anything I have wrong.
Because 7 seems to be an extension of Vista, I'm assuming that Drivers/Compatibility issues involving Vista are the same with 7.

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Here's the situation:

-Windows XP uses XPDM drivers.
-Windows 7 uses WDDM drivers.
-XPDM drivers do not support Aero
-Windows 7 will allow XPDM drivers to operate while running the Basic theme.
-Windows 7 only allows a single WDDM driver to be used at a time (but can be used for multiple cards)
-Windows 7 does not support the use of a WDDM driver and an XPDM driver at the same time.
-If Windows 7 detects multiple cards that are incapable of using the same WDDM driver, it will only install one of the cards and disable the other.
-Windows 7 DOES support the use of two XPDM drivers at the same time (over two different cards)
See here: MultiMonitor Support and Windows Vista

-I have two VGA outputs: Intel 915g (onboard) and NVIDIA Geforce FX 5200 (PCI)
-Intel has not and will not and cannot supply WDDM drivers for the 915g chipset.
-NVIDIA can, and does.
-Intel XPDM drivers will work on Vista (and presumably 7) if installed using compatibility mode [but will only be able to use Vista Basic (no Aero)]

-When I upgraded from XP (where my multimonitor setup worked flawlessly), 7 was unable to find a driver for the Intel chip, but successfully found and installed the NVIDIA card.
-Even if it had found the appropriate XPDM driver for the Intel chip, the card would have been disabled due to incompatibility with the WDDM card.
-I now want to remove the WDDM driver and force install the two XPDM drivers for both the NVIDIA card and the Intel onboard graphics (Which is supported).
-Neither want to install.

Thanks in advance for any help you have to offer, and please, point me in the right direction if I'm off in any way.