Microsoft Loopback adapter
For some reason, the Add New Hardware wizard is missing the Microsoft Loopback adapter in the Control Panel in the Beta build of Windows 7 (build 7000). That makes it rather hard to install the loopback adapter. However, you can actually still start the wizard following these instructions.
Click on the Windows Orb (The old Start button) or press the WIN key.
Select the Install the hardware that I manually select from a list (Advanced) option and click Next.
Select Network Adapters and click Next
Select Microsoft and the Microsoft Loopback Adapter and click Next.
Click Next and you are done.