You can either update the device drivers to see if a newer driver will support sleep, or uninstall them if they are not needed, and then restart the system. The sleep option will then be available.
OR
Use the following steps to determine which of the device drivers do not fully support sleep:
You can run powercfg /a to see what power states the system does not support.
EXAMPLE:
“powercfg /a” output shows on this system that some hardware does not support sleep.
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The following sleep states are available on this system:
Standby (Connected)
Hibernate
Fast Startup
The following sleep states are not available on this system:
Standby (S1)
The system firmware does not support this standby state.
This standby state is disabled when connected standby is supported.
Standby (S2)
The system firmware does not support this standby state.
This standby state is disabled when connected standby is supported.
Standby (S3)
The system firmware does not support this standby state.
This standby state is disabled when connected standby is supported.
Hybrid Sleep
Standby (S3) is not available.
To determine which devices support sleep states, you can run the following commands:
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“Powercfg -devicequery S1_supported”
“Powercfg -devicequery S2_supported”
“Powercfg -devicequery S3_supported”
“Powercfg -devicequery S4_supported”
You would then compare the list to the known installed drivers on the system, and then find those drivers that are not listed in the output from the above commands.