Recording with dual screens
It is fairly common to have multiple screens connected to a PC - especially having a laptop with an external monitor attached to it. UPK will always record the primary screen - this is the one with the Windows Start Menu and Taskbar on it. If you want to record the contents of the second screen, then you need to set the secondary monitor (for example, the external monitor if you are using a laptop) to be the primary screen.
Note that you cannot record both screens at the same time.