Windows 7 + ATI + Output Window On Wrong Screen

This applies to Windows 7 and MXWendler version 4.2 and above with ATI/AMD graphics

Problem

You want to create an output window on the secondary monitor but it jumps on the primary desktop:

Test

1. Create output window without window decoration and exact position and size of secondary output.
2. Open MXW, output window will jump on primary desktop

Solution

1. Create a display group using the Catalyst Control Center.
2. Display group must contain primary and secondary monitor.
OR
3. Make output window eg. 1 pixel larger than needed, eg. 1921x1080 for Full HD

Background

ATI/AMD Catalyst Control Center interprets accelerated fullscreen windows as games and moves them to the primary desktop. This cannot be turned off separately.