The ‘Failed to initialize video device’ error message is usually related to the DirectX driver or display driver, and only happens on with Windows NotifyRDS Desktop Client. Here are some troubleshooting suggestions for resolving this issue:

A.  Verify that DirectX has been installed properly and that Direct3D is enabled, or you could just re-install it to make sure.  This is especially good advice when the Direct3D is not available or disabled.

On the computer in question:

1.  Click Windows Start Menu
2.  In the Search field, type dxdiag.exe
3.  The DirectX Diagnostic Tool window will open. 
4.  Click on the Display tab
5. Navigate to DirectX Features section and see if Direct3D (Acceleration) is enabled.

B. Update your display driver and restart the computer. Updating the driver normally updates support for Direct3D/DirectX.

C. Uninstall Duet Display. Duet Display causes conflicts with DirectX, which results in this error.