With a default installation of Windows 2008 Server there may be a file called C:\hyberfil.sys that can be up to 4GB in size (depending on how much physical memory in the server). This is used by the hibernation function and if you are not using hibernation can be a waste of disk space.

If you do not want to use hibernation and want to remove this file then open a command prompt and run the following:

powercfg /hibernate off

OMG! I can't believe is just that simple as like that. Thanks! Well, it's true that hibernation is just a waste of space. Thanks again. Your post is always so helpful with me.

Windows places a file on your hard drive that it uses when your computer goes into hibernation mode. If you do not use hibernation mode, or your computer does not properly support it, you may want to disable hibernation and clear the file off your hard drive to free up some space (the file will use as much space as you have in physical memory, so if you have 1GB of RAM, it’s going to use 1GB of your hard drive space).

Disable Hibernation:

1. Click Start, All Programs, and then right click on "Command Prompt".

2. From the context menu click on "Run as administrator".

3. If User Account Control prompts you to allow the action, click on Continue.

4. In the command prompt window, type "powercfg –h off" (without the quotes).

5. Close the Command Prompt window.

Delete the Hibernation File:

1. Click Start, All Programs, Accessories, System Tools, and then click "Disk Cleanup".

2. If prompted to choose a drive, select the drive in which Windows Vista is installed on to and press OK.

3. Disk Cleanup will scan the hard drive and present you with a list of options.

4. Check "Hibernation File Cleaner", and then click OK.

5. When asked "Are you sure you want to permanently delete these files?" click on the Delete Files button .