Windows 7: How to install a Lan adapter driver to my desktop?

I bought a second hand desktop yesterday. When I connect my DSL cable to the CPU, the system prompt: no driver found. Since this is a second hand, I don't have a cd for this pc. I'm confused. I really don't know what to do. The owner who sold me this informed me that he used this pc only with wireless connection with his usb type broadband. I don't have a wireless broadband and only using a dsl cable. Please help me fix my pc.

1. Go to start>right click on Computer select manage This opens computer management.

2. Open Device Manager on left.

3. Select Network Adapter...(little arrow beside it)

Write down the name of it and go to a PC with internet and google the name of your NIC with driver download and the version of your OS Win 7 or XP.

EX: Realtek PCIe GBE Family Controller driver download Win 7

4. Copy the driver onto an USB key or burn to cd/dvd or whatever you have to do to transfer it over to the desktop, and install it.

Should give you network access as its obvious that Windows doesn't have the driver or it would of loaded a generic on install.