Here is a tip showing how to enable the network mapping features on Windows 7 machines. The network map feature (which was introduced in Vista) is handy for finding other computers and devices on the network and getting a visual representation of them in the Network and Sharing Center. By default, network mapping is not enabled on computers that belong to Windows domains, but you can enable it via Group Policy. Here's how:

1. Click Start and in the search box, type gpedit.msc and press Enter to open the Local Group Policy editor.
2. Navigate to Computer Configuration | Administrative Templates | Network | Link-Layer Topology Discovery.
3. Double click "Turn on Mapper I/O (LLTDIO) Driver in the right pane.
4. In the dialog box that appears, click the Enabled button.
5. Under Options at the bottom left, check the box that says "Allow operation while in domain."
6. Click the Next Setting button at the top right.
7. Do the same for the Turn On Responder (RSPNDR) Driver.
8. Click OK.

Please note that the gpedit.msc command only works on Windows 7 Pro, Enterprise and Ultimate, and these are the only editions that can be domain members. In a large domain, it may take a very long time to create a network map with hundreds of devices.

source: win7news