Windows 10 can't go to sleep. Sleep states S1-S3 are not available

Solution 1:

It looks like you have these options disabled in your EUFI\BIOS. The exact wording will depend upon your motherboard but the options you are looking for will be under APM (Advanced Power Management) or ACPI (Advanced Configuration and Power Interface)

Here is an article about the topic:

http://www.pearsonitcertification.com/articles/article.aspx?p=2024310&seqNum=21

Your MB has the following relevant options in the BIOS:

• Advanced Menu
• ACPI Settings
• Enable ACPI Auto Configuration [Disabled]
• Enable Hibernation [Enabled]
• IntelRCSetup menu
• Advanced Power Management Configuration
• CPU Advanced PM Turning

Use the APM and Advanced PM Tuning to ensure all the S modes are enabled.

SOURCE: https://dlcdnets.asus.com/pub/ASUS/mb/Socket2011-R3/Z10PA-D8/Manual/E13692_Z10PA-D8_Series_UM_V3_WEB.pdf