Windows 7: hiberfil.sys

Hibernation is turned on by default in Windows 7 and C:\hiberfil.sys is the system file which Windows has always used for_ hibernation._ But, hibernation may not really be needed on workstations which are never turned off. It might be a good idea to turn off hibernation and recover the disk space from hiberfil.sys. The disk space involved can be substantial, for example on my Windows 7 system with 2GB of RAM, C:\hiberfil.sys is 1.5GB.

In Windows XP, hibernation could be turned off from the System dialog. In Windows 7, you need to use powercfg.exe at the command prompt (with Administrator privileges of course):

$ powercfg -h off

No reboot is necessary, the hiberfil.sys file is removed as soon as hibernation is turned off.

If you change your mind later, you can turn it back on:

$ powercfg -h on

For more information, see How to disable and re-enable hibernation on a computer that is running Windows.