The Aten USB to Serial Driver is not very common and has a much smaller market than the other players in the USB to Serial connectors. Gigaware USB to Serial and Prolific USB to Serial are the biggest of the connectors mainly because Radio-shack used to stock many of their products.
If you are stuck while installing the driver you can search other posts such as the FT232R USB driver page which gives a good explanation as to what goes wrong most times and how to install the driver if everything else fails. Below are 2 sets of drivers. The first are the latest drivers while there are legacy drivers for older Windows 98 computers.