Turning off display freezes "underlying display"

I don't know where to start with this problem - if this is not the right section please redirect me. I record certain wildlife webcams 24/7 and extract "events" to upload to YouTube "for the record" and share with other interested parties.

At times I want to switch off the display so's not to give out light and to save power, but need to keep recording. This works fine on Dell Precision M4400 Windows 7 Professional 64-bit, but on Dell Alienware M11x-R1 and M11x-R3, both running Windows 7 Home Premium 64-bit, all I get on completed recordings is a still picture of whatever was onscreen when the display was switched off.

This happens whether I use ControlPanel/PowerOptions settings to turn the display off after so many minutes, or use a keyboard shortcut created with NirCmd (to save disturbing the recording by opening ControlPanel).

As said, I just don't know where to start to figure out why the behaviours are different on the 3 laptops and would be very grateful for guidance.

Sounds like your system is going to sleep and not just turning off the display. No need to go into control panel to turn the display off. Set it to a time period and the display will auto turn off if there is no mouse or keyboard activity. Also set the sleep timer to Never.

clemenzina said:

... all I get on completed recordings is a still picture of whatever was onscreen when the display was switched off.

This happens whether I use ControlPanel/PowerOptions settings to turn the display off after so many minutes, or use a keyboard shortcut created with NirCmd (to save disturbing the recording by opening ControlPanel).

Click to expand...

My settings have been exactly as you suggest
- I end up recording a frozen screen:




However, I don't want those settings to be permanent but to change them I have to open ControlPanel, which obliterates part of what I'm recording. That's why I created the shortcut keys, to switch off the display "at will" without interfering with anything onscreen. Either way, the picture freezes when the display switches off.

Been poking about, found this setting:



The "Sleep after" "Plugged in" setting was 15 minutes so I've changed it to Never. It didn't make any difference - not that it should have because the problem has been that the display freezes immediately the display is switched off