Still using Windows 2000 or Windows XP Pre-SP2? If so, you had better upgrade your operating system. Mozilla’s Asa Dotzler announced that the Firefox team is moving towards using a newer version of the Visual Studio toolchain. Once this is done, Mozilla will no longer be able to build for Windows 2000, or Windows XP SP1.
The share of users still using these two out of date Windows versions is really small, the largest number I saw was maybe .4%? So, if this means that the Mozilla team is able to put out a bigger and better browser, then so be it. Dotzler says, “Next Tuesday or Wednesday, after Firefox 12 moves to Aurora, the Mozilla Release Engineering team will begin upgrading our Windows build systems to Visual Studio 2010.”
In fact, Mozilla has supported Windows XP SP1 and Windows 2000 longer than Microsoft has. Internet Explorer 8 requires XP with SP2 or higher, and has no support for Windows 2000 at all. So if you are still using Windows XP, make sure you are running the latest and greatest version if you want to still use Firefox.