He said his network controller was not showing in Device Manager.
You probably have at least one unidentified device showing in Device Manager, one of them is certainly your Ethernet controller. This is why you always locate your device drivers BEFORE you re-format your hard drive and re-install Windows.
What you're looking for on the first Toshiba link that RandomTox supplied is what Toshiba calls a "Lan Driver", assuming you've got the 32-bit version of Windows 7. If you have 64-bit Windows 7 then use his second link. In either case, download the Lan Driver to another computer and transfer it via flash drive or CD, then install it.