Windows won't connect to a network no matter what I do

Windows won't connect to a network no matter what I do

My windows 7 computer that I just formatted (about 20 minutes ago, clean
install of windows) won't connect to the internet.
Before I formatted it, it worked fine.
Here's what I've tried:
Power cycling my router/modem
Plugging computer directly into the modem
Buying a wifi USB (even though my computer has wifi built in), installed
the drivers from a disc
Windows troubleshooter couldn't fix it. Three other computers in my house
all work fine on my network. I'm assuming I'm missing a driver, however I
can't connect to windows update to get the driver (and, the USB wifi thing
came with a driver disc that I installed)
Right after I run the troubleshooter and connect again, it allows me to
chose the type of network (home, public, work). But it still won't
connect.