The USB driver of USB/RS-422 converter for personal computer loader is stored in the 'UsbToSerial' folder in the 'Driver' folder in the folder where the personal computer loader (SX-Programmer Expert (D300win) or SX-Programmer Standard V3) is installed. Note that if your loader version is old, the USB driver is not stored there. In this case, download 'FLT-ASFKA USB driver' from the 'Fe Library,' the technical information page in the Fuji Electric website. If 'Driver of Fuji UsbToSerial converter” appears in the Start menu of Windows on your computer, execute it to install the USB driver.