Select the Allow incoming echo requests check box on the ICMP tab of the Internet connection firewall settings.

And here’s an interesting factoid. When told to ping your own IP, which IP are they talking about?
You actually have 2 IP’s, although most hackers are only aware of one.

IP #1, the one you’ll find by typing ipconfig at a command prompt is probably what you’re trying to ping. To do that you have to go out to a device, and have it route back to your machine. It’s possible that PING has been disabled at that device.

In the Windows XP Firewall settings:

- Set the firewall to “On”
- Make sure the “Don’t allow exceptions” selection box is left unchecked.
Note: When this check box is selected, the firewall is placed into On With No Exceptions mode which blocks all unsolicited requests to connect to your computer. This includes requests to programs or services that you select on the Exceptions tab. Use the Don’t allow exceptions setting when you need maximum protection for your computer, such as when you connect to a public network in a hotel or airport, or when a vulnerability is discovered and either you have not had time to download a hotfix for your computer or a hotfix is unavailable.

- Configuring the Firewall Exceptions:
- On the Exceptions Tab, look for and click the Add Port button. Assign the name and port number for your Exception. Keep the TCP Option Selected.
- Look for and click the Change scope button.
- Set the Option to Custom List, and input the IP Address and Subnet of the Office Computer.
- Confirm all settings and Save
The Custom List allows only the Office Computer to access the Port of the Home Computer.

Run the Windows XP Network Setup Wizard manually on all the portable computers, as well as the different home computers. This sets up the Home Network or Domain. When setting up the home network, make sure to enable simple file sharing for files and printers.

To access another computer on the network from your portable computer
1. Click Start, click Run, and then type two backslashes and the name of the other computer: \\computername
2. Click OK. A folder containing the shared folders and resources on the other computer will open.

To connect with an IP address instead of a computer’s name
1. Click Start, click Run, and then type the IP address of the computer you are connecting to: \\192.168.0.3
2. Click OK.

These are the steps on how to configure the firewall settings:

1. Click Start, point to Settings, click Control Panel
2. In the Control Panel Window, open Windows Firewall
3. In the Windows Firewall, click the Advanced tab
4. Go to ICMP or the Internet Control Message Protocol and click Settings
5. Select the “Allow incoming echo requests”
6. Click OK