I used hibernation on my Windows 7 Professional 64 bit for almost a year without any issue whatsoever. Last week I was installing service pack 1 ( even though I keep updating my machine whenever there is a new update ). After installing the service pack ( and possibly other updates available that day ) I can no longer put my Windows in sleep or hibernation. Every time I try the machine tries I guess but then simply shuts down the machine without a warning giving me the inproper shutdown screen when booting it up again. I've tried turning hibernation off and on again via powercfg.exe. I even deleted the hiberfil.sys file, performed chkdsk checks etc. Everything seems fine. Anybody has a clue what's going on with my Windows? Is there a way to debug the issue? The log just shows this: "The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly." Any help would be really appreciated as I really want/need hibernation back working.

check this KB article and all suggestions: http://support.microsoft.com/kb/976877/en-us Some users fixed it by disabling the hybrid sleep."A programmer is just a tool which converts caffeine into code" CLIP- Stellvertreter http://www.winvistaside.de/