This is a driver file for a " usb to serial convertor"
this is to enable you to use a [ laptop without a 9 pin com port] . to use a null modem cable to programmer your receiver.
it says plug and play on these devices, they don't and you need a driver, so if your device came without a driver disc use this
it works 100%.
[1] open and run the driver file with the device unplugged
[2] it might ask you to uninstall old drivers [say yes]
[3] re-start your pc after installed.
[4] connect your usb to serial device.
[5] check in the device manager settings
[ prolific usb to serial com port.-com [1].
EDIT:
ALSO HERE IS THE VISTA DRIVER ORIGINALLY POSTED BY A FRIEND
and now the usb to serial driver for windows vista
wd_pl2303h-hx-x_v20019v2021.zip
PL-2303 Vista Driver Installer.zip
USB-UART_Controller.zip