ARHP-990 is the Network Command System (Internet Remote Operation Host) Software for the TS-990S. It's a free download from www.kenwood.com/i/products/info/amateur/software_download.html
To connect your TS-990S to a PC via its USB port, install the Silicon Laboratories Inc. virtual COM port driver (ARUA-10) in the PC first. It's a free download from www.kenwood.com/i/products/info/amateur/vcp_e.html
