Hibernate not available in Vista or stopped working

I do almost all my work from my Dell XPS M1710 laptop.  Today, I needed to take my laptop with me to show some work to a client I had done some development for.  I closed the lid of my XPS and walked out of the room to grab my car keys.  When I returned, I expected my laptop to have hibernated and shutdown, but when I arrived back the lights were still on and after opening the lid I was greeted by the Windows logon.  There was no hibernate.  When I checked the power settings, I could see where hibernate was listed as the choice when I first set all this up but it obviously did not work.  When I clicked on the drop down menu, hibernate was no longer an option.

hhhmmmm…

Personally, I love hibernate.  It has to be the best power feature available.  You close your laptop’s lid, everything gets saved to disk, and the computer turns off.  When you turn your computer back on all you do is type in your password and within a few moments you are right back to where you were.

So what happened to my hibernate feature?  I know my model laptop supports hibernate because it worked before so why does Vista not list it as an option?  In my case, it was because of the disk cleanup utility.  The disk cleanup utility is a wonderful thing as it makes a very simple task of:

* Cleaning up Temporary Internet Files

* Deleting old shadow copies (see a related post)

* Deleting other old temp installation files

And much, much more.  To clean up manually the stuff the disk cleanup utility does in one fell swoop could easily take you 3x the time.  But there is one thing the utility cleans up that is the cause of our problem as the below screenshot indicates:

And there is the cause of our not having hibernation.  The disk cleanup utility wiped out the file Vista uses to store a duplicate of the contents of memory when hibernating.  Apparently, if that file is not present, the power features of Windows assumes hibernation is not available.  Fortunately, the remedy is simple.  On Windows Vista, go to Start | All Programs | Accessories and right click on the Command Prompt icon.  From the menu, choose Run As Administrator.  Then, click OK on the UAC prompt so the command prompt will appear with full Admin rights.  Keep in mind that we assume you are logged in with an account with limited admin rights to begin with, you just need to be elevated once UAC verifies what’s going on.  If you are logged in as a regular user, log out and back in as a user that is a member of the Administrator’s Group or use the built-in Administrator account.  Next, use the powercfg command to re-enable hibernation by typing the following command:

powercfg /hibernate on

Go back to the power settings in Vista and you’ll notice that hibernate is now an option (if it still isn’t, try a quick reboot).

This time, when I closed the lid of my laptop, it hibernated.

JamesNT