Can I mod my driver(s)?

That's not modifying the driver, it's only modifying the install program's .ini file to allow the driver to be installed for a different chipset.

If that mod works for that driver and that chipset you're home free.
Using that technique (modifying a driver's .ini file) with a different driver and or different chipset without knowing exactly what you're doing could easily lead to you asking my favorite computer question ..."Are flames supposed to shoot out of it like that?"

Or you could just buy a video card and get a huge performance boost without risking ****ing something up

EDIT: Apparently your mobo has no pci-e or agp slots, so the best you can do is a pci 4350. It'd still be a decent upgrade.