Was having trouble printing with this printer so I uninstalled the printer and reinstalled it. It will now print but it won't scan. Windows 7 64 bit. printer is hooked to the ethernet switch. Tried downloading new driver but it says latest driver already installed. When I go to the HP solution center to scan it says not connected. plug in your usb cable. It was never connected by USB before. Any suggestions? This printer is used mostly for scanning to Dropbox.