You will not be able to install the latest version of Mozilla Firefox on that laptop because it is running Windows XP, which is not supported anymore. However, you can still use the last stable release supported for Windows XP - [[https://www.mozilla.org/en-US/firefox/52.9.0/system-requirements/| Firefox ESR 52.9.0]] To download this extended support release of Firefox, go to the [[https://www.mozilla.org/en-US/firefox/all/#product-desktop-esr| Firefox download page]] select Windows 32-bit or 32-bit MSI and your preferred language then click download now. Please note that some website may not work properly with this release of Firefox as it does not come with the latest features but it has the latest security and stability fixes. [[https://support.mozilla.org/en-US/kb/switch-to-firefox-extended-support-release-esr| More Info]]