Activating Sleep Mode in Windows Vista



After owning a fully functioning (as much as one would expect) computer with Windows Vista for several years, the Sleep function stopped working correctly.
Previously, the power light turned off, the fan stopped, and it took a press of the power button, or at least several reasonable mouse-wiggles to wake it up again.

One day, it no longer worked. Just cut out. As far as I know, nothing else out of the ordinary happened, and I can't think of anything I changed that could have affected it.

The command and button shortcut still respond, but both instead send the computer into a very 'light sleep', where the screen simply turns off, as it does after being left alone after a length of time. The fan still goes, it's too easy to wake up, and most of the time as soon as the screen says 'No Signal', it wakes up again on the 'User Locked' screen.

I miss the old Sleep mode, so I was wondering if some light could be shed on the matter.

Thank you.
Have you recently connected a USB device ?
If so check the USB settings in Power Options (Advanced)
Hmm, not that I can think of...

I did just try messing around with the power settings, both resetting them and then testing likely causes, and I seem to have stumbled across the solution, somehow, as the Sleep function now works correctly. I did already try this before though, so I'm not entirely sure as to what I did differently.

Thanks for the help anyway. Sorry for wasting your time on it.