I’m not sure the reason for the hibernation file hiberfil.sys being enabled in a default Windows 2008 Server install, but use this to remove it:

powercfg.exe /hibernate off

If for some reason you need to put it back, use:

powercfg.exe /hibernate on

You need to use this command, as this setting is unavailable in the GUI. This also can apply to Windows 7 especially after a P2V.