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Please note: I am not looking for a solution to the problem. I am looking for how I can get extra information to figure it out... give a man a fish, he's fed for a day. You know the rest.

This is a DIY system using:

  • SUPERMICRO MBD-C2SBX+-O LGA 775 Intel X48 ATX Intel Motherboard
  • Intel Core2 Quad Q9400 2.66GHz LGA 775 95W Quad-Core Processor
  • XFX HD-489A-ZDFC Radeon HD 4890 1GB 256-bit GDDR5 PCI Express 2.0 x16 video card
  • Various other pieces of hardware I don't consider relevant

The issue is that Vista does not put the system to sleep. The monitor will be put to sleep, but not the system itself. The led on the lid doesn't blink, and the watts used at the wall socket only goes down minutely. If I use the Start Menu and manually put the computer to sleep, then it does sleep. The watts used goes down dramatically, fans power down, and the led blinks. I can wake up in the morning, and the system still isn't alseep. Something's amiss.

I searched through the Vista power settings, but can't find anything. It seems odd that the default behavior would be not to sleep.

I've looked through my motherboard manual looking for power management options. I found in the BIOS a setting that lets the processor switch power modes between "G1/G3 without C", "C", "G1/G3 and C", "C without G1/G3", or disabled. After educating myself on what these mean, I set it to use both. But no change in behavior. I also tried removing all USB devices.

After trawling the Internet using Google, I haven't come across this specific issue or how to solve it. So the question becomes, how do I get more information on what the issue is? Are there tools I can use to gather data on why Vista requires me to nanny? I've looked at the event logs but nothing there seems relevant.

How should I proceed with my diagnostic process?

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The behavior that you expect hasn't been clearly defined in the question. You mentioned that Vista will sleep if you manually make it sleep; did you want it to sleep after the computer's been idle for a while? – Babu Aug 31 '09 at 22:22
Your description of what happens when you manually force "sleep" mode matches what happens when I "sleep" my computer. That said, Vista couldn't "sleep" my Dimension 5150 computer; installing Windows 7 fixed the problem. – David Mackintosh Sep 1 '09 at 0:35
up vote 2 down vote accepted

Here is an interesting troubleshooter for Vista sleep problems. Scroll down the website for the steps.

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If you have used the Disk Cleanup Utility and utilized it to clear the hibernation file, you may be surprised to find that the Hibernate option is no longer available. You can restore the hibernate option by following these instructions:

  1. Click the Start button.

  2. Select All Programs.

  3. Select Accessories.

  4. Right-click on Command Prompt.

  5. Select Run as Administrator.

  6. When the UAC prompt appears, click Continue.

  7. Type powercfg /hibernate on and press Enter on your keyboard.

  8. Close the Command Prompt window.

  9. Reboot your PC.

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I had a similar issue before too - Vista machine simply would not sleep.

The best place to look for information would be the Event Viewer tool.

Start > Run > eventvwr.msc

under "System" you should find some errors that gives clues as to what is stopping the system from sleeping - in my case it was my wireless drivers. Updated them and was perfectly fine after that.

So, use Event Viewer as a stepping board to narrow your troubleshooting scope, it's really useful.

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