Using the RadControls for WinForms Dock Visual Studio IDE example program simply do the following:
Drag the RadButton Toolbox onto the Document panel.
The Toolbox is now shown as a Document and it is not possible to drag it back to where it was before the move.
Found the answer myself:
The context menu (right click on the tab) contains more entries than the normal document windows one of which is "Floating".
Selecting this function returns it back into a Toolbox window.
Drag the RadButton Toolbox onto the Document panel.
The Toolbox is now shown as a Document and it is not possible to drag it back to where it was before the move.
Found the answer myself:
The context menu (right click on the tab) contains more entries than the normal document windows one of which is "Floating".
Selecting this function returns it back into a Toolbox window.