SIS 900 is a network chip (not a pci network card). SIS does not make network cards.... they are only a chipset maker. They also sold this chipset to hundreds of motherboard makers.
If you want specific Foxconn drivers, then please say which Foxconn motherboard you have and state whether it's a retail or OEM motherboard. If it's a retail motherboard, you should be able to find drivers for it on the manufacturers website providing you can determine what Foxconn mb. you have. Also, you need to say if it's intergrated on a desktop or laptop computer.
Open Device Manager, double-click the network device, (it may be listed under "Unknow Devices"), click the Details tab, select "hardware id's, then give me the hardware id string that begins with PCI\VEN, (1st. line of text only).
You can see all SIS 900 drivers posted in our driver database by clicking the HOME button (upper left of this page) and use the Simple Search
button to locate exiting "SIS 900" drivers posted in our driver database. That's not to say that all of them will work but it's a starting point with what vague info I have to work with. You can also use the Advanced Driver Search Wizard
to accomplish the same task.
You can also check the SIS website to see if they offer this driver.
And last, there's a link (within the HOME button) that will give you a link to the new beta DriverScan 2011
program. It does not install anything on your computer, it's simply an EXE file that you run by double-clicking it. When accomplished, it will provide several choices to download the correct driver. Don't be afraid to use it as it's clean and doesn't put any junk on your pc.
You should spend a few minutes reading the Beginners Guide
posted in links at the bottom of this page.