FIREWALL

Check Personal Firewall Status Tip:

In the previous tip, I mention how to turn on Windows XP's Personal Firewall feature. But once you turn it on, your connection looks just the same as it did before. How can you check the status of the connection and the firewall? Simply open Control Panel from the Start Menu, open Internet and Network Connections, then Network Connections. By default the view is of large icons.
Click the View Menu, and choose "details" in order to reveal several more columns of information about the connections that your computer has. Check the Status column to see if your connection is currently connected, and whether or not it is "firewalled." You can even drag the column headings around (I like to slide the Status column right next to the Name column. You can even remove entire columns by right-clicking the column heading and unchecking it.