It's 08-10-15, just upgraded to Start 10. When the installer ran, it never displayed anything after the initial start up. The SRV file was running in the background, but there was no indication that Start 10 was either running or installing. Still had the Start 8 service running.

Upon logging off and on again, the Start 10 window opened asking for the activation key.

Entered the key, and activated. As soon as I did, my desktop started flashing on and off! That's a first with anything but a video driver update.

So, I know it's beta, but what doesn't it like about Windows 10 or nVidia drivers?