1 - download the latest driver here:
2 - unzip the files to a location you will remember.
3 - plug in the USB data cable
4 - the "found new hardware" wizard should appear.
5 - choose to "install from a list or specified location" and click "next".
6 - put a "check" in the checkbox labeled "include this location in the search", and then click "browse".
7 - browse to the location where you unzipped the files.
8 - it should find the driver: "prolific usb-to-serial comm port" and install it. click "finish".

changing to proper xp driver

1 - click "start"->"control panel".
2 - double click "system".
3 - select the "hardware" tab.
4 - click the "device manager" button. the device manager window should open.
5 - click the small "+" sign next to "ports (com & lpt)".
6 - click on the "prolific usb-to-serial comm port" (if you can not see it. go to 'trouble shooting')
7 - click the menu item "action"-> "update driver".
8 - this starts the "hardware update" wizard.
9 - choose to "install from a list or specified location" and click "next".
10 - put a "check" in the checkbox labeled "include this location in the search", and then click "browse".
11 - browse to the location where you unzipped the files.
12 - it should find the driver: "prolific usb-to-serial comm port" and install it. click "finish".

trouble shooting:

1. 'usb device' with question mark in 'device manager: other devices'.
2. right click mouse, click 'properties', select 'install driver'.
3. browse to the location where you unzipped the files.
4. it should find the driver: "prolific usb-to-serial comm port" and install it. click "finish".

support:

how do i change to a different com setting?

the way to change the com port is by changing the i/o range for it in device manager.
right-click on my computer
click the device manager tab.
click the + by ports
select prolific usb to serial port (com5)
click the properties button
click the resources tab.
uncheck the box that says use automatic sttings .
select the input/output range
click the change settings button.
click the little arrows until you find an appropriate setting. 02e8-02ef should give you a com4 setting after you restart the computer.
make sure to click ok on all screens.