it's the Desktop Playground that comes with DTX (the wall says Magic Desktop)
I just ran it
Playground is set to hide the icons and taskbar
if you bought the full dtx or package that come with dtx builder - right click on the desktop > in the menu click
desktop x > switch to builder - then after builder mode comes up right click on desktop and choose builder > configure builder
when to window pops up, in the desktop tab you can uncheck hide the icons and/or hide the taskbar
if you only have the client version of dtx (no builder) then right click on the desktop > in the menu click desktop x > unload and all should come back
I just created a taskbar and blew up the desktop due to the physics handler getting errors - guess it's due to the various object states built in the option (gravity, etc)
Playground is kinda old - using the add an item option - the windows come up blank for shortcuts, etc and there doesn't seem to be a browse option