i used to hibernate my computer rather than shutdown but lately i reinstalled windows xp and installed a hotfix KB896256 that told me to make an entry in the registry at the location... HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager . besides i have installed deepfreeze too... . now my computer cant hibernate even when i disable deepfreeze. the error given to me when i say 'enable hibernation' is this -> "Power policy manager unable to reserve hibernate file" "A Device attached to the file is not functioning" . is this because of deepfreeze or the hotfix or just some setting that i have changed?