Firefox no longer works with some versions of Windows XP
Windows XP with Service Pack 2 is the minimum Windows version that meets the Firefox System Requirements. We'll explain how to find out your Windows XP version and what to do if you're using Service Pack 1 or below.
How to check which Windows XP Service Pack is installed on your computer
- Click on the Windows button and open the Control Panel.
- Click on the Performance and Maintenance link (Category View only), then click on System to open the System Properties window.
- In the System Properties window, select the General tab. Within the information in the General tab, it will tell you which service pack is installed (if one is installed).
Service Pack 2 or 3
If it says Service Pack 2 or Service Pack 3, your system meets the requirements for the latest Firefox version. For more information, see How can I get the latest version of Firefox on Windows XP or Vista?
Service Pack 1 or nothing at all
If it says Service Pack 1 or nothing at all, your system doesn't meet the Firefox system requirements. The only popular web browser that is still being updated with security patches for older versions of Windows XP is Opera.
To download and install Opera, visit the Opera website.