Figuring out why your PC doesn’t go to sleep can be a challenge, not least because there aren’t usually any error messages to help. Could it be a software conflict, a hardware problem, a configuration issue? There’s no way to tell.

If you’ve been left baffled, though, you may be able to get just a little help from PassMark Sleeper. The program has no magic solutions (this is too complex a topic for that), but it does offer some useful features which might take you a little further forward.

Sleeper is a ridiculously small download (164KB), which unzips into the folder of your choice. Close down all your other programs, launch Sleeper, and it’ll immediately tell you which sleep states it thinks your system supports (S1, S2, S3 or S4; if the system doesn’t support something you were expecting then that could be your problem), and whether the computer should be able to wake up after some predetermined delay.

Does sleep work in practice, though? Click “Sleep Now” and the program will try to make your system sleep for 30 seconds (at the default setting), waking it up afterwards.

Experiment with sleep options and the left-hand log records exactly what's happened

If this doesn’t work at all, choose a difference sleep state in the “Suspend Types for Cycle” box and try again. You might run through S1, S2, S3 and S4, for instance, regardless of that the program says is supported.

Or maybe your sleep issues seem to be intermittent? Sleeper can run its Sleep test repeatedly. Click Configuration, enter the number of runs you’d like in the “Number of Cycles” box, and click OK. Now click “Sleep Now” again and the program will try to send your PC to sleep for a few seconds, then wake it up again, repeating the process for as many times as you’ve specified, and logging the results.

At the end of all this, at the very minimum, you’ll have confirmation of the problem (if Sleeper can’t make your system sleep, either). But the program may also have revealed useful system information (various sleep states aren’t supported), and of course you might have found that your system can sleep, after all, as long as it’s set to use the correct sleep state.

Sleeper’s abilities don’t stop there, though. Because if all you want is a shortcut you can use to make your PC sleep, then the program provides an extensive command line interface which should help. You can choose your sleep state, duration, and force the system to sleep, for instance (useful if some application is trying to block your request).

Put it all together and that’s really not bad, especially for such a tiny and free (for personal use) executable. So the next time your PC has insomnia, give Sleeper a try – it’s a surprisingly capable tool.