I had a big black window appear when I was in Mac mode, indicating it was a Parallels window. The text of the window is New USB device detected, and below that symbols of a Mac and a Windows display, and the selection that can move from one to the other to select which the USB plugin applies to. I selected the Mac and pressed the Option key to remember the choice. My main problem is that I cannot figure how to get rid of that window. There is no button area at the corners, or anything on the window that tells me how to do that, and there is nothing in the Parallels menu at the top of my screen. Certainly there must be a way to get rid of it without either shutting down my Mac, or shutting down Parallels. Has anyone else had this problem and solved it?