I have a windows 7 x64 machine which sometimes (not all the time - no discernable pattern) when I tell it to sleep turns off the monitor but never powers off the machine (left it overnight). It then won't wake up, tried the keyboard, mouse and power button.
to be clear the machine turns the screen off like it is going to sleep, but then the fans/disks/cpu do not turn off and the power light on the front of the machine stays on. Once it is in this state it can then be 'woken'
My only option seems to be to hard shut off and reboot.
Why might this be?