Loop back adaptor for Windows 7

The key step I was missing was how to find the Hardware Wizard:

1. Click the Start menu.
2. Search for “cmd".
3. Right-click on “cmd” and select “Run as Administrator”
4. Enter “hdwwiz.exe”

From that point on it's the same approach as under Vista, i.e.:

1. In the "Welcome to the Add Hardware Wizard", click Next.
2. Select "Install the hardware that I manually select from a list (Advanced)" and click Next.
3. Scroll down and select "Network adapters" and click Next.
4. Select under Manufacturer "Microsoft" and then under Network Adapter "Microsoft Loopback Adapter" and click Next.

I've tested this and it's working for me (connecting the host to a VPC using the loopback adapter).