It seems you have connected your phone without drivers installed in your system. Please uninstall Windows MTP drivers for your phone from Windows (in Device Manager) and install our driver pack or visit the manufacturers' website and get latest drivers for your device.
Android
In case you use an Android phone which has been connected as MTP you can still manage your files.
iPhone
Sometimes Windows does not install the driver correctly and you have to reinstall it manually. MOBILedit Phone Manager can do the job for you or you can do it in Device Manager.
