I've been struggling for months now to get Elite working in VR again on windows 10. I've finally found a way that works that some might find acceptable/useful.
Essentially the problems for me began when windows switched from it's WDDM 1.3 to WDDM 2.0 which gives access to the (forthcoming) features of DX12. Upgrading to the WDDM 2.0 enabled driver sets has broken rift usage for me in windows 10 whilst using SLI.
A lot of people seem to think SLI doesn't work with the rift - but for me its the difference between mostly stable when active 75fps and not anywhere near that when switched off. I honestly don't notice any latency and this is in a 3 way 760 SLI setup. (I won the third card in a competition - with some poetry I might add! - before you flame me for the build xD)
I struggled in vain for ages trying to get the runtime switcher to work but even when it switched to 0.5 (steamvr doesn't support/use SLI for me) it would crash my PC. I literally thought I had a hardware issue with my GPUs.
However today it dawned on me the problems began with the DX12 driver branch so I went back and re-installed 347.88 enabled the runtime switcher to 0.5 and now SLI functionality has returned and works flawlessly!
I realise this won't be an acceptable solution for some who need the most up to date drivers for more recent games but I really only play Elite in VR and DOTA 2. So I'm super happy!