I upgraded my system to windows 7 ultimate 32 bit a few weeks back.
At that time the on board network adapter was visible and everything was running smoothly.But since last few days the OnBoard Lan has disappeared !!!
In the DEVICE MANAGER there are NO Network Adapters Visible..Even After i Run scan For Hardware changes.....
I have an DLINK DFE 520-TX Lan Card...I plugged it in one of the PCI slot....And now the REAL Problem Starts....
In the DEVICE MANAGER..The Card is visible under Network Adapters..But it shows a error message that Windows cannot load The drivers required for this Device..
So i Uninstalled it and did Scan for Hardware Changes...It again Detects the Card But Immediately The BLUE SCREEN OF DEATH(BSOD) is Flasshed and the pc gets restarted...I even tried installing the driver from the Dlink CD..But of no use..It still says cannot load the driver !!!
And everytime I do Scan for new hardware It flashes The BLUE SCREEN and Restarts...On the Microsoft Website they have mentioned that for the DFE520-TX
Did you try deleting the currently installed drivers and installing the new ones from DLink site instead? I rarely use Microsoft for any driver updates. If this doesn't solve the issue since it's a recent installation you may just want to start from scratch and use newly downloaded driver. That being said there is probably a simple registry fix for this issue. You aren't alone by the way - There is a wireless PCI card from Linksys that was sold with one model number but over time used 3 different chips. Of course Microsoft only had one driver so you can imagine how annoying i was when it wasn't for your chip.