Hi,
I bought a Acer W700 Core i3 Version recently. Now I updated to Windows 8.1 64bit preview over MS Store and tried a bunch of drivers already. The one from Windows Update, the most recent one for Windows 8 from here and after some checking in google a revision 3190 which seems to be the most recent right now. All are MS signed and all work to an extent.
Only problem. Theres no D3D acceleration at all. DXDIAG tells me that theres no DirectDraw Acceleration and No AGP Acceleration at all and D3D is said to be active, but its not. All applications using it fail with a error message telling me theres no D3D compatible GPU installed.
Well.... is this known? I have no clue if I had this in Windows 8, too. I almost instantly updated to Wihndows 8.1.