Send it the right signal.
Seriously, what kind of answer do you want? Kudos for providing a picture of the symptom, but you've provided very little information other than that. We can see you're running Windows from your screenshot, but you haven't told us about any software you're running or hardware in your rig.
See the post "Soft15KHz" stickied above for ideas, as well as the "PowerStrip" thread.
Unless you have an ArcadeVGA, which is another ball of worms entirely.