How do I disable the Windows XP firewall so that I can install Zone Alarm?

Windows XP firewall is enabled by default whenever a connection is created. After creating either a dial up or LAN (Local Area Network, such as for wireless) connection, go to "Start", "Control panel", then "Network Connections". Right click the connection to be changed and choose "Properties" from the menu.

Then choose the "Advanced" tab in the "Properties" window and under "Internet Connection Firewall" uncheck the box for "Protect my computer...."

With the latest Service Pack (SP2) there is a separate plug-in in the Control Panel for managing the firewall. In XP Home it's called just Firewall or Internet Connection Firewall. In XP Pro it may be called the same or may be Security Management Console or some variant.

This info changes with each Hotfix for the patches for the last Hotfixes.