On the Select Network Adapter1 screen, click the Have Disk... button.
Note: You don't need to select a Network Adapter here. The zero, one, or more entries in that box don't directly represent the actual device(s) you have installed but instead represent the available drivers that Windows 7 has for this particular piece of hardware. By clicking Have Disk... you're skipping this existing driver selection process and telling Windows 7 that you have better drivers you'd like to install that it isn't yet aware of.
[1] The name of this screen will be different depending on the kind of hardware you're updating the drivers for. A more generic Select the device driver you want to install for this hardware is common.
