By default Windows will search the Windows Update website for device drivers if it can't find the drivers it needs within the local driver store. This behavior can be disabled using Group Policy by configuring the following policy setting:
Computer Configuration\Administrative Templates\System\IDevice Installation\Specify search order for device driver source locations
Simply enable the above policy setting and the select Do Not Search Windows Update in the Select Search Order control.
But what if you want to prevent Windows from searching online for device drivers during the process of deploying Windows to a destination computer? In that case, you can add a task sequence step that runs the Apply_LGPO_Delta utility created by Aaron Margosis, which can be used to automate custom changes to the local policy of the Windows installation being deployed to the destination computer.
You can find Aaron's utility here:
Mitch Tulloch is a seven-time recipient of the Microsoft Most Valuable Professional (MVP) award and widely recognized expert on Windows administration, deployment and virtualization. For more tips by Mitch you can follow him on Twitter or friend him on Facebook.