Disable Hibernation
Unlike other versions of Windows Hibernation is part and parcel of the shutdown options of Vista. There are no options in Power options to actually disable it. If you don't use it then hibernation will be taking up valuable disk space, therefore it is easier to disable the option and reclaim the disk space allocated to the hiberfil.sys.
To disable hibernation proceed as follows:
1/ Open a Command prompt
2/ At the command prompt type: powercfg -H off