By default Windows 7 will permanently consume a chunk of your hard drive with its hibernation file (up to 4gb), but if you never use sleep, and always turn your PC off, then this file will never actually be used. To disable hibernation and recover a little space, go to the Registry Editor and look for the following string:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power
In the right pane, double-click on the 'HibernateEnabled' and 'HiberFileSizePerfect' DWORD Values and set the Value Data to '0'. Once you reboot your computer, the Hibernate file will automatically be deleted.
