Windows Tip Sheet

When the Firewall Burns

Troubleshoot your Windows Firewall with these key tips.

The Windows Firewall included in WinXP SP2 usually works fine...but when it doesn't, troubleshooting can be a real pain. Microsoft offers a troubleshooting document in its Knowledge Base; here are some key tips from that doc and my own experience:

  • When possible, create firewall exceptions for applications, not ports. That way the firewall can just allow applications to use whatever ports they need, and you don't have to guess what those are.
  • Use netstat –ano to identify ports in use by running applications.
  • Run tasklist > tasklist.txt and tasklist /svc > services.txt to get a process and service inventory.
  • Run firewall.cpl and, on the Advanced tab, modify the security logging settings to create a firewall log. This is a great way to see what the firewall is up to, but be sure to turn logging off when you're finished.

By looking at the log and seeing what the firewall is doing, and by figuring out exactly what exceptions need to be made for something to work, you'll be able to configure the firewall accurately in less time, and with less trial-and-error.

Additional Resources:

About the Author

Don Jones is a multiple-year recipient of Microsoft’s MVP Award, and is an Author/Evangelist for video training company Pluralsight. Don is also a co-founder and President of, a community dedicated to Microsoft’s Windows PowerShell technology. Don has more than two decades of experience in the IT industry, and specializes in the Microsoft business technology platform. He’s the author of more than 50 technology books, an accomplished IT journalist, and a sought-after speaker and instructor at conferences worldwide. Reach Don on Twitter at @concentratedDon, or on Facebook at

comments powered by Disqus

SharePoint Watch

Sign up for our newsletter.

Terms and Privacy Policy consent

I agree to this site's Privacy Policy.