Repairing a Network Connection

If you came to Vista from Windows XP, you may have come across the latter's network Repair tool that did an okay job of repairing connectivity problems because most networking problems can be resolved by running the Repair tool's basic tasks: disconnecting, renewing the Dynamic Host Control Protocol (DHCP) lease, flushing various network caches, and then reconnecting.

Unfortunately, the Repair tool would all too often report that it couldn't fix the problem, which usually meant that the trouble existed at a level deeper in the network stack than the Repair tool could go. In an attempt to handle these more challenging connectivity issues, Vista comes with a completely redesigned Network Diagnostics tool that digs deep into all layers of the network stack to try to identify and resolve problems. Vista gives you several methods of launching the Network Diagnostic tool:

• Right-click the notification area's Network icon and then click Diagnose.
• In the Network and Sharing Center, click View Status, and then click Diagnose.
• If you lose a connection to a network share, Vista displays a Network Error dialog box to let you know. Click the Diagnose button.
• In the Network Connections window, click the broken connection, and then click Repair This Connection.

When you launch the diagnostics, Vista invokes the new Network Diagnostics Framework (NDF), a collection of tools, technologies, algorithms, programming interfaces, services, and troubleshooters. The NDF passes the specifics of the problem to the Network Diagnostics Engine (NDE), which then generates a list of possible causes. For each potential cause, the NDE launches a specific troubleshooter, which determines whether the aspect of networking covered by the troubleshooter could be creating the problem. For example, there are troubleshooters related to wireless connectivity, Transport Control Protocol (TCP) connections, address acquisition, and many more. In the end, the troubleshooters end up creating a list of possible solutions to the problem. If there is just one solution that can be performed automatically, the NDE attempts the solution. If there are multiple solutions (or a single solution that requires user input). Click the solution or follow the instructions that appear.