I dunno... Luke seems to understand what he says. And if R2 can interface with some random Imperial computer network, I trust he could interface with something as simplistic as a PC. And since when does diagnosing a computer's problems involve a USB2 port? Last I checked, it involved typing and mousing around and possibly even pulling it apart. With all the stuff I've seen R2 interface with as well as pull apart and fix in both the OT and PT, I think he could handle it. 3PO just gets tangled up in cables.

Oh, and somehow I don't see 3PO on his knees scrubbing my kitchen floor.

I think R2 would be the perfect tool to have to interface with any and all electronic devices I own or would want to own.