The Gigaware USB to Serial Driver is nothing more than another USB driver from Prolific. The installation process has been explained here (FT232R USB UART Driver). The driver has been added below for the Gigaware version of the software. If it does not work then take a look at the Prolific original drivers.
Prolific made a number of products in the USB to serial range and Gigaware was only a generic copy of the original hardware. You can download the driver below. If it does not work – check the original post for assistance.
In order to install this driver you will need to download the zip file above and extract the content. What you should have is the following in the directory where you extracted the file. You will note that there is an .inf file called SV9PL.ing. You will need to right-click on that file.
Once you right-click on the file you will see the following options on your new menu
You will then need to click on the install option and the driver will then install the serial driver for you. Note again that this is a Vista / Win7 / Win8 driver and it is only the inf file so it cant be run in compatibility mode. Most of the drivers on this website tends to be mainly for older computers.
This where the drivers are becoming increasingly hard to find even though the hardware is still around. Some hardware might not be for that specific hardware but the chipset may be the same as someone else’s hardware. The features might thus be limiting. Having said that however it normally still gets you to operate the device in its usable mode. The Gigaware USB to Serial Driver is no different as Gigaware used a Prolific chipset.