Back in the days when I still used to have Windows I would use K-Meleon as my web browser. It uses the Mozilla Gecko engine and runs well on Linux (over wine) as well. It doesn’t have the bells and whistles of Firefox but it is much faster and a full-featured browser. I can see that the development is not very active but the latest Beta would be good enough to run on Windows XP or Windows 7. Download from the project website.