Heres my problem: * I leave my computer (desktop) unattended for 1 hour +. The screensaver starts after 5 minutes (I have checked the "On resume, display logon screen" option). The display then shuts off automatically after 30 minutes (as I have chosen in my power options) but the computer never goes into sleep mode. Here is what works: * If I manually lock my user session and *then* leave the computer unattended for 1 hour +, the screensaver starts up, and eventually the computer automatically goes into sleep mode after the 1 hour timeout. *If I manually choose sleep from the shutdown options, the computer goes into sleep mode as expected. (I have set the sleep timeout in my the power options to 1 hour. Also, the 'Turn off the display' time out is 30 minutes) Configuration: (from msinfo32.exe) OS Name Microsoft Windows 7 Professional Version 6.1.7600 Build 7600 Other OS Description Not Available OS Manufacturer Microsoft Corporation System Name XXXXXXXXXX System Manufacturer OEM System Model OEM System Type x64-based PC Processor Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz, 3000 Mhz, 2 Core(s), 2 Logical Processor(s) BIOS Version/Date Phoenix Technologies, LTD 6.00 PG, 12/24/2008 SMBIOS Version 2.5 Windows Directory C:\Windows System Directory C:\Windows\system32 Boot Device \Device\HarddiskVolume1 Locale United States Hardware Abstraction Layer Version = "6.1.7600.16385" User Name XXXXXXXXX Installed Physical Memory (RAM) 8.00 GB Total Physical Memory 8.00 GB Available Physical Memory 6.09 GB Total Virtual Memory 16.0 GB Available Virtual Memory 14.0 GB Page File Space 8.00 GB Page File C:\pagefile.sys

The issue is media sharing over the network. In your Power Options, click Change when the computer sleeps and then Change advanced power settings. In the dialog that opens, scroll down to "Multimedia settings" and expand it. The When sharing media section controls this behavior: Description of Options: • Allow the computer to sleep will allow the computer to sleep, regardless of what initiates it (manual or timer) • Prevent idling to sleep is the default. This lets the computer sleep if you tell it to, but not on a timer (so that it doesn't interrupt media sharing over the network). • Allow the computer to enter Away mode is a special mode where the computer appears to be asleep, but keeps essential functions for sharing running. If this was helpful, please vote by clicking the green triangle. If it solves the issue, click Propose as Answer. Thanks!

Its already set to 'Allow the computer to sleep' Not sure if you missed it in the original question, but my problem is that the the sleep timeout works only if I manually lock the machine. If I do not, it doesn't work.

That's what this option causes: if it is not set to "Allow to sleep" for all power settings and battery configurations, it will cause your computer to only sleep when you manually choose to -- never automatically. If you have already checked all power profiles and battery configurations for this, then this is not the cause. Another thing to check would be driver updates from your manufacture. Let me ask, was this an issue always, or did it used to work before this issue began? Did you upgrade to Windows 7, or did the computer come with it? If this was helpful, please vote by clicking the green triangle. If it solves the issue, click Propose as Answer. Thanks!

Your reply pointed me in the right direction and I figured out the problem. I had followed a stupid windows services guide and disable some services and a few among them were the media player/center ones. I reenabled all of the ones i had disabled and now sleep works without locking the computer ! Yay !