How to use the D3DKMTInvalidateActiveVidPn function to change desktop display settings in Windows Vista

This article contains information about how to use the D3DKMTInvalidateActiveVidPn function in Windows Vista. This function invalidates the video present network (VidPN) that the video graphics driver is using.

Typically, you use the ChangeDisplaySettingsEx function to set the desktop display settings. However, on a display device that uses the Windows Vista graphics driver model driver, third-party programs and utilities can use the D3DKMTInvalidateActiveVidPn function to set display settings.

When you use the D3DKMTInvalidateActiveVidPn function, Windows Vista queries the third-party kernel-mode driver. Therefore, you have more control over the settings than you have when you use the ChangeDisplaySettingsEx function. However, the D3DKMTInvalidateActiveVidPn function does not include a complete superset of the Microsoft Windows graphics device interface (GDI) display configuration API. Also, the D3DKMTInvalidateActiveVidPn function always resets a multimonitor desktop to the default configuration. Therefore, you may have to use the ChangeDisplaySettingsEx function after you use the D3DKMTInvalidateActiveVidPn function so that you can successfully take the following actions:

• Change the primary display
• Extend the desktop to a second display and then set the relative position of the displays

Note Because this process requires two steps, the screen may flash two times as the new settings are applied.

For more information about the D3DKMTInvalidateActiveVidPn function, visit the following Microsoft Web site: