I upgraded a dell E5400 laptop to WIndows 7 professional. Sometimes when I enter sleep mode, the screen goes black like it should, but then the system hangs and never goes to sleep. After 10 minutes the computer powers off. When I turn it back on, I get the "windows did not shut down properly" screen and I choose to "start windows normally"
I used all the "official Dell" Drivers for Windows 7.
I don't see anything in Event Viewer that indicates a specific device is causing the SLeep to hang.
I ran Sigverif.exe. All of the "unsigned drivers" are related to my Printer (a brother MFC 8860DN, and I'm using their Windows 7 drivers) and "igfxress.dll" and "igfxtray.exe". Those are related to INtel Video, but again I'm using dell's "official" windows 7 drivers so I don't see why they should be causing the hang either.
Thanks for your help,