Windows 11 No option to sleep

I'm a big advocate of using "sleep" on desktop computers.  The S3 power state puts your computer into a deep sleep, turning off most of the things that pull any significant power (such as the CPU).  Memory though is retained, so when you turn on the computer again, you get an almost instant-on and return to where you were previously.

Historically people tended to avoid sleep on desktop computers because if the power is lost, so is whatever is in memory.  Hibernate is a deeper sleep state that writes the memory to disk, but also then needs to read that memory from disk when the computer turns on, whilst still usually quicker than a full boot, it's not an instant-on affair.

Hybrid Sleep came on the scene many years ago which combines these.  When your system goes to sleep, it will dump the memory to disk, and then go into standard S3 sleep mode.  The benefit for this is that you still get instant-on from sleep, but if the power is lost, your system will still come back in its previous state.

But, on a new Windows 11 system I'm working with, sleep has gone completely.

Sleep fix

There are plenty of articles out there on how to tick the box for sleep in the power options, but what if it's not an option?  The sleep option has completely gone for me.  We need to troubleshoot a bit by running: powercfg /a.  This command lists all the available sleep states and if they're not available, why not.  I was presented with this:

    Standby (S3)
        The current Device Guard configuration has disabled this standby state.

Device Guard is a virtualisation technology that allows Windows to protect some core system components from malicious attack.  Seems like a great idea, but frustratingly, is incompatible with sleep.  I guess Microsoft's Windows engineering team aren't facing a cost-of-living-crisis at the moment and can afford to keep their computers on all the time!

Removing it is simple enough, navigate through Windows Security > Device Security > Core Isolation; and disable 'Firmware Protection', you will need to reboot.

Hybrid Sleep

Additionally, it seems that virtualisation is also blocking Windows 11 to be able to make use of Hybrid Sleep (as discussed above).  Likewise, when we check our power states with the above command, this is what is presented:

    Hybrid Sleep
        The hypervisor does not support this standby state.

This is more tricky to narrow down, and it seems several things can trigger it, including "Memory Integrity" in the same area as the above issue.  Basically it seems that anything that utilises HyperV under the tin, will cause this problem.  Bizarrely, it doesn't also seem to apply to hibernate and sleep, and given that hybrid sleep is a combination of the both, I find that perplexing.

I cannot find any documentation on the Windows 11 implementation of Hyper-V, but a 2016 article on HyperV for Windows Server 2012 explicitly states that this concept is supported.  It looks like another oversight.