You should be able to dock it through drag & drop (it may take a few tries though).

Worst case you can reset the whole interface: http://www.mediamonkey.com/support/index.php?/Knowledgebase/Article/View/151/0/reset-mediamonkey-for-windows-interface-to-defaults

Hello,
I am having issues with a detached video window, I accidentally detached it from the main program.
How do I reattach it to the main GUI?
I tried moving it over the place I want to put it but it seems to act like a complete separate program?

Regards