That means that Windows 8 7899 is the first build to support UEFI w/o CSM, but I need to verify it first UPD: @yescn , could you send me proof of successfully running Windows 8 7899 on VirtualBox with UEFI enabled? Because I am not going to spend many hours to download Windows 8 7899 just to test if it is UEFI class 3 capable or not
Ok, then try 7904 Server (on UEFI class 3 PC), 7927 and 7955 x86 (on VirtualBox with UEFI enabled, but however, you may need to manually install it via deploying install.wim, because only 7927's install.wim leaked, and 7927 iso in the internet uses Windows 7 RTM x86 PE, which is not compatible with UEFI at all (does not matter that UEFI with or without CSM)), and 7962 and 7963 x64 (optionally try x86 version of 7963)
Try to install it from DVD if you have it, and Windows 8+ have built-in USB 3.0 drivers, but... stop, USB 3.0 drivers was introduced in Windows 8 7814, but maybe it not compatible with your USB 3.0 controller, but... if you have only USB 2.0, then... still try to run 7899's setup from Windows 8+ PE
Windows 7 drivers might be compatible with Windows 8 7899, but Windows 8 drivers... I don't think that it will work with 7899
I used generic USB driver ported from 8 to 7 and it worked and i installed the beta on it on UEFI class 3 laptop