Fixing Hibernate Problems in Windows Vista

One of the most regularly reported problems with Windows Vista is that the hibernate function - one of the power-saving modes - does not work. I have been using Vista daily since February 2007 and although the experience has been generally positive, hibernation has failed to work a number of times. Through trial and error (and a lot of time spent trawling through blogs of both users and Windows developers) I have come across some solutions that seem to work for most people.
Hibernation problems on Vista fall roughly in to three categories:

the computer fails to wake up from hibernation
the computer fails to hibernate
the computer keeps waking up from hibernation when it is supposed to be sleeping
Waking Vista from hibernation
The number one reason that Vista fails to wake from hibernation is a problem with video drivers. In my case, the answer was simple. All I needed to do was to update the drivers for my Radeon Xpress 1150 onboard video chipset. A quick visit to the ATI drivers page to download the latest drivers and I was back in business. As easy as that.
Making Vista hibernate
Sometimes the hibernation option is not available, or your hardware key combination (on my Dell it is Fn -> F1) simply does not work. The first thing you need to check if your computer supports one of the hibernation options. To do this, go to the start menu and type Command in the search box. In the results, right click and select “Run as Administrator”. When the command prompt opens up, type powercfg "a, which shows you all of the available types of hibernation that your hardware supports. In the video below you will notice that my laptop supports s(3) which is the “deep hibernation” that saves the state of the system to disk before shutting the hardware down.
If your hardware does support hibernation but it still stubbornly refuses to bunker down for the winter, either the hibernation option has been disabled or the Hibernation File Cleaner has been deleted by the Disk Cleanup Utility. Both these options are easily fixed using the powercfg utility again. To turn hibernation back on, type powercfg -h on.
I can personally vouch for this method as well. Like many people, when I first ran the Disk Cleanup Utility, I saw the the Hibernation File Cleaner took up around 1GB of disk space and I thought “Surely it wouldn’t be an option if it wasn’t safe to delete it? Surely?” Like many people I learned the answer was “Hmm. Not so much” which isn’t exactly grammatically correct but does get its meaning across while inspiring a healthy dose of Friends nostalgia and yearning for Courtney Cox that I thought had long since worn off. Not so much, obviously. But I digress. In my case, the option to hibernate had disappeared from my shut down options and Fn -> F1 didn’t work either. powercfg -h on worked immediately.
Vista Keeps Waking Up From Hibernation
This one is a tricky one. In theory, hibernation physically shuts down your machine so issues such as scheduled tasks (eg system updates, virus scans and so on) shouldn’t be able to wake the machine back up. However, I have seen reports all over the internet of Vista machines waking up and doing strange things. I have never experienced this problem myself but the following suggestions have worked for various people at various times:

If your computer wakes up at a consistent time, make sure there are no scheduled tasks (Start menu -> search for “task scheduler”)
Check your BIOS settings to make sure that “Wake on LAN” (also sometimes known as “Wake on Ring”) are disabled. Check your bootup screens to see what key combination you need to hit to access your BIOS
Check in Device Manager (Start menu -> search for “device manager” - your life will be much easier if you run this program as Administrator) and see if any of your devices have an option that allows it to wake the computer. I’ve seen reports that blame everything from a wireless mouse to an ethernet device that isn’t plugged in to the network for waking a computer from hibernation.