At the PC side you need driver software (winxp and lower) but for win7 up no need driver.
Complete Circuit/Driver/Schematic can download at HERE
Installation HOME MADE USB - Serial Converter:
- Connect the USB cable to a PC's USB port and USB port Home Made this circuit
- Power LED indicator will indicate the presence of active voltage source Module enters the This circuit
- Windows will ask for the driver of the module to be installed
To testing connection use Hyperterminal