This problem is faced only if your Windows 7 or Windows Vista computer is running the Aero graphics mode and it is subject to additional security restrictions and security software you are very likely to experience this issue. Let’s say your Windows computer is locked and left undisturbed long enough for the screen to go black, which is 20 minutes with the default power policy of “Balanced”. Now you unlock the computer by entering their user credentials. After the credential is entered if the screen goes black and remains black for as much as 10 minutes or longer, then check the solutions mentioned in KB2431700. A temporary workaround is to Stop and Disable the “Desktop Window Manager Session Manager” service. Disabling this service will turn off the “Aero” graphics display feature, which will disable certain features such as Aero Peek, Aero Snap, Aero Shake, and so on. To disable this service:
Click the Start button, type “services.msc” and then press the ENTER key, or click the icon that comes up under “Programs” in the Instant Search box.Locate and then double-click the Desktop Window Manager Session Manager service.Locate the “Startup type” dropdown and change the value to “disabled”.Locate and click the button labeled “Stop”.Click the Apply button, and then click the OK button.
Alternatively you can run the following commands from an elevated CMD prompt to set the service properties of the Desktop Window Manager Session Manager service to not running and disabled: To return the settings for the Desktop Window Manager Session Manager service to normal via the CMD line: You may also see if updating your display drivers resolves this issue. See this post if you have Windows 10 Black Screen problems.