I do not know Digital Rights Management is associated with your problem. It would seem the unit would have to be able to communicate with the computer before it would even know if something was not appropriate.
Have you tried different USB connections. The unit is USB 2.0 perhaps it would function better in a 2.0 plug.
Basically, I do not know what is wrong. If all your other USB devices function, maybe there is some driver problem and Win 7 does not have a driver for this unit.
I still cannot tell who makes it. It has an Epson screen, so does Epson make it, even though it probably doesn't make a difference, but you might check the manufacturer for a driver.
When you plug it in, what type of messages do you get?