https://www.mozilla.org/en-US/firefox/43.0/system-requirements/

Thank you for your response. It looks like I should have downloaded Firefox to my old computer before Microsoft stopped supporting IE 8, as my IE is no longer working and I am unable to connect to the internet.

Download Firefox from here - https://www.mozilla.org/en-US/firefox/all/ - on a PC that does have a browser, and transfer it to that WinXP PC via a USB Flash stick.

Thank you for your help. This worked perfectly!

Ask this: Can I download Firefox to a thumb drive and run it from there? in Google. There are several articles to read. This is an edit from an answer on Mozilla Support: You may consider using the portable Firefox as it can even run with Profile completely from the usb flash drive. It is not done by Mozilla however. Portableapps has been a trusted download option for several years now with the portable Firefox version. http://portableapps.com/apps/internet/firefox_portable. "My old computer" implies that you have a new one. If not ask a friend to download it for you. I use XP as well and I may be able to help with the memory issue, Feel free to Private Message me about it.

I should have refreshed the tab before I posted. Glad to see things worked out.

Mozilla Firefox, Portable Edition {web link} A fully functional package of Firefox optimized for use on a USB key drive. A specialized launcher will allow most favorite extensions to work as you switch computers.

FredMcD, the portable Firefox version was already mentioned and linked to ;)