After upgrading from 8 to 8.1 my computer no longer sleeps after several minutes of inactivity.

I'm able to force the computer to sleep by using Win+x, Shutdown, Sleep, and that works fine. I've reset the power plans to default and tried changing the times to something else. The only thing that seems to work is setting the hibernate function. However, as seen below S3 sleep is supported and when my computer does not sleep I check the powercfg /requests all the time and see nothing in there. Any ideas guys?

[1056]: powercfg /requests
DISPLAY:                  
None.                     
                          
SYSTEM:                   
None.                     
                          
AWAYMODE:                 
None.                     
                          
EXECUTION:                
None.                     
                          
PERFBOOST:                
None.                     

[1057]: powercfg /a                                             
The following sleep states are available on this system:        
    Standby (S1 S3)                                             
                                                                
The following sleep states are not available on this system:    
    Standby (S2)                                                
        The system firmware does not support this standby state.
                                                                
    Hibernate                                                   
        Hibernation has not been enabled.                       
                                                                
    Standby (Connected)                                         
        The system firmware does not support this standby state.
                                                                
    Hybrid Sleep                                                
        Hibernation is not available.                           
                                                                
    Fast Startup                                                
        Hibernation is not available.                       

• Edited by Nathan_M Saturday, September 14, 2013 9:15 PM Formatting

So I added in these settings, left the computer alone for 1 minute, the display turns off, I wait another 3 minutes and we never hit hibernate or S3 sleep. Just nothing happens, I then hit up powercfg /requests (shown below) with the same as usual, nothing running results.

[1078]: powercfg /requests
DISPLAY:                  
None.                     
                          
SYSTEM:                   
None.                     
                          
AWAYMODE:                 
None.                     
                          
EXECUTION:                
None.                     
                          
PERFBOOST:                
None.

Open Network and Sharing Center and click on Change Adapter settings.  Right-click on your adapter and select Properties. Uncheck Internet Protocol Version 6 (TCP/IPv6) and click OK. Then open Device Manager, right-click on your Network Adapter and select Properties > Advanced and click once on Send Large Offload v2 (IP/v6) to highlight and set the Value to "Disabled", then click OK and restart your PC.

Ref: How to Disable IPv6 in Windows 8 (Please note that modifying the registry is not required if you follow my proc

Carey, I think we have a winner! Any idea how someone who didn't know this magic trick could determine what was causing this?

Follow these steps:

a.       Press Windows key + W from the keyboard.

b.      Type Troubleshooting without quotes in the search box.

c.       Select Troubleshooting option from the list.

d.      Select View all option from the left panel.

e.      Select Power and follow the on-screen instructions.

I did this one a few times and it always told me there was nothing to change or do.

After further review, and another reboot, this no longer seems to work. I've timed several 1 minute sleep/hibernate tests and the PC no longer sleeps with the requested settings in place. I still have no idea how to troubleshoot this in any way other then the guess work behind ipv6 going bonkers.

[1027]: powercfg /requests
DISPLAY:                  
None.                     
                          
SYSTEM:                   
None.                     
                          
AWAYMODE:                 
None.                     
                          
EXECUTION:                
None.                     
                          
PERFBOOST:                
None.

Try the suggestions outlined in this article: Information about power management setting on a network adapter

My suggestion for the Power Management settings for your Network Adapter:

• Place a check next to "Allow the computer to turn off this device to save power"
• Uncheck "Allow this device to wake the computer", then click OK.

P.S.  If you happen to have a desktop computer with a RealTek PCIe GBE adapter, you can download and install the latest Windows 8.1 driver version from here.