From VNC Server 6.11.0 you can blank the screens of computers that are running Windows 7 or later. This allows you to control to a remote computer without people in the vicinity seeing what you're doing. This is an update to the screen blanking for Windows 10 that was added in VNC Server 6.3.2.
Note: You cannot blank the screens of remote Linux or Mac computers.
How do I enable screen blanking?
Open VNC Server's Options > Privacy page and turn on Blank screen when users are connected.
Once enabled, ensure that VNC Server's Users & Permissions are also configured to allow screen blanking:
Note: Screen blanking is hardware-dependent for Windows 8, so we recommend you test these systems first to make sure screen blanking will be effective. Avoid any users connecting remotely while a blanking test is in progress as it can prematurely blank the screens.
What operating systems support screen blanking?
Currently only Windows is supported, from Windows 7 up to and including Windows 11.
For Windows 7, Windows 10 version 2004 and later, and Windows 11, screen blanking is controlled by software so it should be effective on all hardware, including laptops.
For Windows 8 and Windows 10 versions prior to 2004, screen blanking is hardware dependent. Most desktop screens manufactured after 2011 should be supported, including major manufacturers such as Dell and Samsung. The screen must have an independent power button; all-in-one computers are unlikely to work. Unfortunately, there is not as much support for laptop screens, which are also unlikely to work.
How long does screen blanking last?
For Windows 7, Windows 10 version 2004 and later, and Windows 11, screen blanking is active whenever there is a VNC Viewer connected. Note, there are some known issues that affect screen blanking. These are:
- The mouse cursor is visible on the VNC Server computer's display/monitor
- When clicked, some menu items on system tray icons are briefly visible on the VNC Server computer's display/monitor
- Screen blanking is interrupted when using Windows' Desktop Peek feature
- Screen blanking is interrupted when hovering on an application's taskbar thumbnail
For Windows 8 and Windows 10 versions prior to 2004, VNC Server attempts to make screen blanking last for as long as possible. Screen blanking ends if:
- The blanked screen is powered on again.
- Screens are added or removed from the system.
How do I know if screen blanking is enabled?
When a VNC Viewer is connected to VNC Server and screen blanking is enabled, VNC Server will display a privacy badge on its icon in the system tray, next to the clock. Look for this icon:
What if I can’t get screen blanking to work?
For Windows 7, Windows 10 version 2004 and later, and Windows 11
Contact our support team here, including a debug server log.
For Windows 8 and Windows 10 versions prior to 2004
Assuming that your screen was manufactured after 2011 and is not a laptop display, you can try the following:
- Remove any base stations, splitters or repeaters used to connect your screens.
- Update your graphic card driver software to the latest version.
- If there is an option on the screen’s setup menu called MCCS or DDC/CI, enable that option.
If you need to contact our support team, we need the following information:
- A debug server log, after you have performed the screen blanking test.
- The manufacturer and model of the screens that failed to respond to screen blanking.
- How the screens are connected to your system (HDMI, VGA, DVI, and so on).
- The manufacturer and model of your graphics card.
Article is closed for comments.