My router ENHWI-G2 is not working on windows vista

I have an ENHWI-G2 encore wireless router. i tried to install it in windows vista but always unsuccessful. unsuccessful in a sense that even though it was already installed eh hindi naman gumagana dahil ang sabi eh the windows cannot load the drivers required for this device (code 31). Then iyon realtik wireless LAN utility box niya eh empty o walang laman.
Ini-update ko na rin siya sa internet for Driver Software for REALTEK 8185 Extensible Wireless Device eh sabi naman eh "the best driver softwate for your device is already installed and the windows has determined that the driver software for my device is up to date. kaso sa Device Manage eh naka yellow naman siya at ang sabi nga eh the windows cannot load the drivers required for this device (code 31).
thanks if anybody can help me.