Hiberfil.sys

Hiberfil.sys:

• How to delete it
• What is it's function?
• How do I use it?

In theory, it is supposed to be a quick shortcut or power saving option that allows you to leave your PC in suspended animation until you are ready to work again. However, in practice, most people find little time difference between shutting down and using hibernation. For people who use drive imaging to backup their system, the hiberfil.sys file can bloat the backup files - making them larger (sometimes over 1GB bigger!) and therefore slower to copy/restore.

Hibernation temporarily 'freezes' the computer when the PC becomes inactive, so it won't work if you have tasks running constantly (eg downloading files). However it can be handy if you want the computer to sleep after a task has completed (such as creating a video).

OK, that's the role of hibernation - so what is the hiberfil.sys file and why is it so big? Hibernation takes everything in memory and writes it to your hard drive as the hiberfil.sys file. If you have 512MB of memory, then hiberfil.sys will be about 512MB. If you have 1GB, the file will be around 1GB. The important point to remember is that even if you don't use hibernation, hiberfil.sys will still take up this huge amount of disk space. The way to remove the file is to turn off the hibernation feature (by default, hibernate is activated automatically when XP is installed). Here's how to do it:

• Open the Windows Control Panel
• Double-click Power Options
• Click the Hibernate tab, de-select the 'Enable hibernate support' check box, and then click Apply.
• Restart your computer and hiberfil.sys will be automatically deleted.
• If you change your mind in the future and would like to use hibernation, go to the Windows Help & Support Center and search for 'enable hibernation'. It should be the first result. The instructions detail some other steps you may need to follow to reactivate the hibernation.