I have Intel Chipset Graphics, and according to HP, its embedded in the motherboard and unable to upgrade !?
Is there not an option for you to add a higher graphics card via a PCI(e) or AGP slot ?
Downloaded some new drivers, but unfortunately My Base Score is still at 1.0 -even after refreshing,(due to the Gaming Graphics score) every other score is above 3.
Your low gaming graphics score should have no bearing on desktop display abilities, only your 'desktop performance to run Aero' score. If, as you say, that is above 3, then you should be able to run Aero and the WB tranpsarency/per pixel features should run the same as they do in XP.
I know this doesn't help you much, but someone more knowledgable will have more insight on this than I....posting the system display properties from your WB config in XP & Vista may also help.