Greetings solkeys!

Alternatively you can try this addon . In the settings there is an option - the combine of windows.

I hope this answer helped you

Thank You.What I am trying to do do is combine the three windows into one

You can drag tabs from one window and drop them on the Tab bar of another window to move the tab to that window. The window closes automatically when all tabs have been moved. This can also be used to undo accidental tearing off and move a Tab to a new window (right-click: Move to New Window).

Thank You again. Now it worked I drag the tab not the window and moved up between the tabs not at the taskbar.