In short, no. Longer explanation, look at the nvidia drivers (same goes for ATi). nvwgf2um.dll nvwgf2umx.dll are 32/64 DX10/11 drivers,
you can safely delete them, reboot and still have aero, because aero works off nvd3dum.dll and nvd3dumx.dll
(which are 32 and 64 bit drivers for D3D9).
You know, this is very funny, if I ever relied on that kind of "sources trust-me-bro", I would make zero drivers for Vista.
Also, looks like you weren't paying attention because the OP wrote, DX11 doesn't work, but aero does.
And DX10 is in one file with 11, so it is not loaded at all. DX11 is pretty much DX10 with stuff added upon.
EDIT: *hint* you can see in the .dll's description yourself what are they for exactly.