When Zonet was in business, they did provide technical support for their products through an online support website.
However, since they're no longer operating, that site no longer exists. You'll now need to rely on
other sources for drivers or your previous downloads and discs.
You may find some useful information in an archive copy of their site
here.
Some readers have reported that
Tenda, which is still in business, may have made much of the hardware for Zonet, meaning that the firmware and drivers available from that site may work for your Zonet hardware.