Any way to turn on NMP without using button on back?

[FrancoisC]

For some reason, on windows 8.1 I no longer have a sleep option so turn it off every night - maybe a quirk with the nMP install, as 8.1 on the rMBP has the sleep option

Do you have thunderbolts devices connected? Apple disable sleep for bootcamp (and linux too) if thunderbolt is used.

 

[jenzjen]

Do you have thunderbolts devices connected? Apple disable sleep for bootcamp (and linux too) if thunderbolt is used.

Yes Apple thunderbolt displays

 

[FrancoisC]

That's the reason sleep won't work.

In this case, it's Apple's fault. If you plug this monitor (or any thunderbolts devices) on a PC motherboard with thunderbolt you won't have this problem. One way to fix it on a Mac is to install windows in UEFI mode.

As soon as BIOS emulation mode is loaded on a Mac sleep/standby is disabled if anything use the thunderbolt(s) port(s). (Not applicable for displayport monitors: same connector, different signal)