some applications can prevent windows from going into sleep mode(e.g: connectify hotspot), in these cases, the monitor (laptop's screen) turns off and windows try to go into the sleep mode but because these kinds of application won't allow windows to do so, it stays at this state (screen is off while system is still running and there's hard disk activity) and you no longer have control over your system to bring it back;
the only solution now is to cut off power;
as you know windows has forceful shutdown/restart; in this case windows bypasses applications preventions and successfully does restart/shutdown;
what about forceful sleep?
is there any way to know which applications are preventing windows from going into successful sleep mode?
OS: Windows 7 Ultimate x64
Ctrl+Alt+Deland selecting sleep from the drop-down menu of the power icon on the splash screen with the green arrow options "Switch User", "Log Off", "Start Task Manager", etc.? ("Sleep" via tiny arrow beside red power icon near lower right corner) – A.M. Jul 27 '13 at 17:50Ctrl+Alt+Delhave no effect at all? How about the sleep button or power button?) If you end up giving up on that for now and rebooting, do you mind trying what I suggested? – A.M. Jul 27 '13 at 18:04