I imagine ring0 is the only place we're going to get any glory here. If i have some extra spare time in the next few days I'll do some poking around, but I'm no driver guru, so if anyone has any hits I'd appreciate them.

Ehtyar.

[edit]
Found some interesting info here at OSROnline (surprise surprise). It would seem you can send an IOCTL to your monitor to get it to turn off, and windows will not interfere. Of course for the average user this may be a problem if the application were to crash or whatever, but in this case i believe it would be the perfect solution. Unfortunately i am not even close to the level of experience required for something like this so perhaps someone else *prods f0dder?* is up to the task.
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Ehtyar.

Found some interesting info here at OSROnline (surprise surprise). It would seem you can send an IOCTL to your monitor to get it to turn off, and windows will not interfere. Of course for the average user this may be a problem if the application were to crash or whatever, but in this case i believe it would be the perfect solution. Unfortunately i am not even close to the level of experience required for something like this so perhaps someone else *prods f0dder?* is up to the task.

I found similar info on MSDN late last night.

If his display supports a brightness level of 0, it could probably be done.

There are 3 different related IOCTL's for this to find out what is supported, what the current settings for both AC & DC are, and to change them.

Just like you, this isn't something I feel comfortable messing around with, and I really have no way to test anything I could possibly make, any way. I don't have a laptop and my LCD monitor most likely doesn't support DC power levels.

are you still looking for a solution musicman?

I have a post in Developers Corner: OCX or API call to control notebook LCD brightness

I am close to my solution and was alerted to your post. I need to ask you what is an obvious question to me. Why would you ever want to turn the display back on? I ask this because you can solve your problem easily by:

1. Disconnecting the graphics/monitor plug on a PC
2. Disconnecting the florescent tube plug on an LCD/notebook (internal)

If those two solutions are not fitting your needs then maybe another simple method that I wrote a few years ago will. I wrote it due to ummmmmmmm "prying eyes". The application is rapid acting since it sits silently in wait for you to press a "hotkey". Once you do this it opens full screen and covers the entire screen with total blackness. To get your screen back you need to enter a password of you choosing.

It doesnt actually turn the screen off but its a fast screen cover and nobody can override it without shutting the computer down. No I am not selling it .... just wrote it for myself and its too simple to make money off of! LOL