When connected "wirelessly" to the router, it should perform as a Network Printer with full functionality available to all computers in the network. If you had to revert to USB, it would be plugged into one computer and have to be "shared" with other computers in the network. The PC to which it is connected would have to be running and only that PC would be able to use the Scanning/Copying functions. "File & Printer Sharing for Microsoft Networks" doesn't support Scanning.
Does the printer support an ethernet connection? That would allow it to be networked properly, if the "wireless" connection doesn't work reliably.