Welcome to Windrivers! Per Realtek's site:
# Q9: Why don't I find RTL8201x driver on the website?

A9:
RTL8201, RTL8201BL, RTL8201CL, RTL8201CP, RTL8201N and RTL8211B(L) are all PHYceiver. That is a driverless hardware device. Software driver are relative to Network controller ( MAC ) which is integrated into chipset in such case mostly. Please contact your mother board maker or chipset manufacturer to obtain proper driver support.

Since, I don't know of any manufacturer offering Vista support for your chipset, I think you're in the market for a new NIC.