If you have got one of these Prolific USB to Serial R232 connector for console access; chances are it will not work on Windows 8.
I have managed to find a driver online and it seem to have fixed the issue.
Please make sure to install the driver via Device Manager => Update Driver => Browse my computer… => Let me pick from a list… => Have Disk and Browse the driver and locate it.
The driver is in a .zip format and you need to unzip it before installation. You may download the driver from here.
Please note, I have not created this driver, nor do I take any responsibility whatsoever could it cause any harm to your device. YOUR USE OF THIS DRIVER IS AT YOUR OWN RISK.