Missing Ethernet Network Controller

Hello,
I need to reinstall my ethernet network controller. Here is the info;

Mainboard : Gigabyte GA-K8N-SLi

>> General Information
Manufacturer : Gigabyte Technology Co., Ltd. (Gigabyte)
Product : GA-K8N-SLi
Version : Unspecified
Serial Number : Unspecified
Support MP : Yes, 1 CPU(s)
Version MPS : 1.4

I used the referred program and it came up with;

Chipset: AMD 800
Computer Name: WINXP_PRO
OS: Microsoft Windows XP Service Pack 3 (OEM)
Device Tree
Other devices
Ethernet Network Controller
Unable to Detect, Hardware ID: NVNET_DEV0057

Please tell me what I need to download, and what I need to do with it. I have been at this since 10:30pm, & its 9:14am. Having a little trouble focusing. TIA