My main PC is using an ASUS M2N-E Mobo which uses nforce drivers and I haven't had a problem at all getting online since build 6801..
I'd take a look in device manager and make sure there aren't more drivers missing.... If there aren't then you'll just have to search for the correct drivers.. which shouldn't be too hard to find.. Also, make sure it's nforce drivers you need.. I thought that board used a Marvell Gigabit Lan Driver...? I'd suggest using the latest available Windows Vista drivers (as they are suposed to work with 7) or the latest Windows 7 drivers (if available)...