I'm on Windows 8.1 x64, with an AMD R9 390. Every time I launch SteamVR, my computer BSOD's with a 'Video_Scheduler_Internal_Error' message.
So far, I've tried:
1) Clean OS reinstall
2) Clean driver removal with DDU, and several versions of AMD drivers (16.5.2, 184.108.40.206, 16.5.3, 16.6.1)
3) sfc /scannow
4) Reinstalling steam
5) Removing and reinstalling SteamVR (both branches, beta and normal)
6) Installing a few random windows components (AMD support seemed to think I needed a different .NET version as well as one of the VC redists, which didn't make sense, since SteamVR would just fail to start if they were missing)
7) CPU/GPU stress testing (Prime95 + Furmark at the same time, no stability issues)
I'm out of ideas here, this seems that SteamVR is triggering some bug in the AMD display drivers. I currently have a ticket open with AMD (8200692012), but so far support seems focused on suggesting things that I've already done.
The one suggestion I've seen here is to upgrade to Windows 10, however that's not really an acceptable solution IMO.