Home now.
So....
It's either a
1) Software issue
2) Hardware issue
Since you're having weird things happen with network card,
new wireless card, graphics....
I was betting on software. Since we know the old card used to work, I was trying to get it to work by reinstalling the drivers.
So go into
device manager, find the network card, delete it. Rescan will get Windows to re-load the drivers. Sometimes, this works if the drivers are messed up (a software issue).
I'm not any more convinced than Tibs is. But who knows? Hard to tell from here. Last I knew, you had a working network card but no network address handed out by the modem/router so they were sending you an new modem/router. Then, a bunch of phone tech support people basically told you that the net card was bad, but nothing has worked since, and now they claim the graphics card is bad. So IDK.