Hibernation is a term used for laptops and portable computers. Windows Vista (like XP before it) supports the industry standard power management technology known as the Advanced Configuration and Power Interface (or ACPI). This allows the operating system to control power to the computer's disk, monitor and peripheral devices.
The power management features in Windows Vista include Hibernate and Standby.
- Hibernate saves an image of your desktop with all open files and documents to your hard disk. This will create a hidden system file called hiberfil.sys, with the size of your installed physical memory on your system partition (usually the C: drive). The computer uses the hiberfil.sys file to store a copy of the system memory on the hard disk when the hibernation setting is turned on. If this file is not present, the computer cannot hibernate. After it stores the information in the file it will power down your computer. When you turn on power, your files and documents will open on your desktop exactly as you left them.
- Standby reduces the power consumption of your computer by cutting power to hardware components you are not using. Standby can cut power to peripheral devices, monitor and hard drives, but maintains power to the computer's memory so you don't lose your work.
These features make most sense if you use a laptop. You can take advantage of the Standby and Hibernate features which reduce the drain on battery power when you leave your laptop running. When you install Windows Vista on a laptop computer, in most cases it will AUTOMATICALLY enable hibernation.
To do this, follow these steps: Open Command Prompt with administrative privileges. In order to do that please follow the "Quickly Open Command Prompt Here in Windows Vista" article. Next, type in the following command:
powercfg -h on
Note: The powercfg command has many interesting options and can be used to automate the creation, deletion and configuration of power plans for your computer. Type powercfg /? for extensive help options.
Note: If you run the Disk Cleanup wizard in Windows Vista Enterprise, you will not be able to put the computer into hibernation. This problem occurs if you select the Hibernation File Cleaner check box when you run the Disk Cleanup wizard. Hibernation File Cleaner removes the hibernation file and turns off hibernation.
To resolve this problem, re-enable hibernation.
Not everyone needs the capabilities of hibernation in their laptop computers. One thing is the huge hiberfil.sys file that will be created in the root of your system partition (usually C:). If you disable hibernation you will also save valuable disk space, especially when considering the fact that Vista already takes around 10 to 11 GB of disk space (after installing Office 2007 and a couple more applications, nothing fancy or big), not including the pagefile.sys file which too will take as much as your installed RAM.
And another thing: I, for one, found out that hibernating my laptop is bad for my personal needs, mostly because when you resume your working state you find that any virtual machines you had running (even if they were saved BEFORE entering hibernation) will stop responding properly. So I simply use Standby (or Sleep) mode on my working laptops.
Note that the hibernation status of your laptop has nothing to do with actual system performance, however the fact that it is enabled causes less disk space to be available for other purposes.
Open Command Prompt with administrative privileges. In order to do that please follow the "Quickly Open Command Prompt Here in Windows Vista" article.
Next, type in the following command:
powercfg -h off
There is no need to reboot the computer and the hibernation file will be automatically deleted.
The hybrid sleep feature and the hibernation feature in Windows Vista may become unavailable after you use the Disk Cleanup Tool - 928897 http://support.microsoft.com/kb/928897
How to disable and re-enable hibernation on a computer that is running Windows Vista - 920730 http://support.microsoft.com/kb/920730
You cannot put the computer into hibernation after you run the Disk Cleanup wizard in Windows Vista Enterprise - 929846 http://support.microsoft.com/kb/929846
Powercfg Command-Line Options http://technet2.microsoft.com/WindowsVista/en/library/1d58b934-f56a-4796-b2df-7be2eb9c03bc1033.mspx