Windows 7 : Troubleshooting Your Network - Diagnostic Tools (part 2) - Network Diagnostics, Event Viewer

3. Network Diagnostics

Windows 7 features a network repair tool called Network Diagnostics that is said (by Microsoft) to be capable of recognizing and diagnosing more than 100 network problems. I’m skeptical of claims like this, but, on the other hand, it takes only a few seconds to let Network Diagnostics examine your network and offer whatever advice it can, so it’s absolutely worth a crack.

To run the Network Diagnostics tool, open the Network and Sharing Center . Click Troubleshoot Problems. Then, select one of the network troubleshooters:

• Internet Connections— Select this if you are having a problem reaching the Internet or just a particular website.

• Shared Folders— Select this if you can’t access a network shared folder whose name you know.

• HomeGroup— Select this if you are having problems accessing a homegroup.

• Network Adapter— Select this if you are having general problems accessing the Internet and/or network resources.

• Incoming Connections— Select this if other computers can’t connect to your computer’s shared files or to other programs or services that you want to make available on your computer (for example, Remote Desktop, a web server, and so on).

• Connection to a Workplace Using DirectAccess— Select this if you can’t access your corporate network over the Internet via the DirectAccess virtual private networking feature.

Windows will display a box that says “Identifying the problem...” and will then display a results window that explains what was found to be wrong, what Windows did about it (if anything), what the outcome was, and where to go for more assistance.

If the diagnostics tool doesn’t solve your network problem, check Windows Firewall to be sure it isn’t blocking a desired network service.

4. Windows Firewall

Another configuration setting that could prevent file and printer sharing from working correctly is Windows Firewall. To ensure that file and printer sharing isn’t blocked, open the Windows Firewall window by clicking Start, Control Panel, System and Security, Windows Firewall. Windows Firewall is much improved in Windows 7, and can filter network activity based on the type of network to which you’re attached. So, in Windows 7, for both Home or Work (Private) networks and for Public networks, the Windows Firewall State should be On, and Incoming Connections should be set to Block All Connections to Programs That Are Not on the List of Allowed Programs.

Click Allow a Program or Feature Through Windows Firewall to view the settings. File and Printer Sharing should be checked, but not in the Public column. Core Networking should be checked in both columns.

5. Event Viewer

Event Viewer another important diagnostic tool and one of the first to check because Windows often silently records useful information about problems with hardware and software in an Event Log. To check, open the Event Viewer: Click Start, right-click Computer, select Manage, and then select the Event Viewer system tool. Start with Custom Views, Administrative Events. This provides a view of all significant management events from all of the various Windows events logs (and there are a lot of them!).

If nothing useful appears there, select Windows Logs, and examine the System, Application, and Security logs in turn. Finally, open Applications and Services Logs, Microsoft, Windows, and under any of the network-related categories, view the Operational and Admin logs.

Event Viewer displays Event Log entries, most recent first, on the right (see Figure 3).

Figure 3. Event Viewer might display important diagnostic information when you have network problems.

Log entries for serious errors are displayed with a red X in a circle; warnings appear with a yellow ! in a triangle. Informational entries (marked with a blue i) usually don’t relate to problems. Double-click any error or warning entries in the log to view the detailed description and any associated data recorded with the entry. The Warning entry in Figure 3 indicates that my computer couldn’t acquire a network address in a reasonable amount of time. It turns out that my router had come unplugged.

These messages are usually significant and informative to help diagnose network problems; they might indicate that a network card is malfunctioning, that a domain controller for authentication or a DHCP server for configuration can’t be found, and so on. The Source column in the error log indicates which Windows component or service recorded the event. These names are usually fairly cryptic. Table 21.32 lists a few of the more common nonobvious ones.

If you’re at a loss to solve the problem even with the information given, check the configuration of the indicated component, or remove and reinstall it to see whether you can clear up the problem.

6. Device Manager

Hardware problems with your network card will most likely be recorded in the Event Log. If you suspect that your network card is the culprit, and nothing is recorded in the Event Log, check the Device Manager.

To use it, click Start, right-click Computer, select Manage, and choose the Device Manager system tool. Any devices with detectable hardware problems or configuration conflicts appear with a yellow ! icon when you display the Device Manager. If no yellow icons appear, you don’t have a detected hardware problem. This doesn’t mean that you don’t have a problem, but the odds are slim that your network card is the problem.

If devices are shown with ! icons, double-click the device name to see the Windows explanation of the device status and any problems. A device that you’ve told Windows not to use (disabled) will have a red X on it; this is generally not a problem.