Fill out your system specs.
From google, all I got for "zonet" is a PC hardware brand, nothing specific, and "sis 900" I see a ethernet adapter.
For the ethernet adapter you can place your driver disc in and manually point the "unknown device" to the disc, it should find the correct driver on its own for it, but you have to point it to that discs dir. I had to do this with my ethernet adapter.
Let me know what you mean by "zonet".