The instuctions that I provided are from this page this page for anyone who is seriously interested in running newer versions of Firefox on Windows 2000. Before you run it on a real machine, I recommend that you test the installation in a virtual machine installation of Windows 2000 itself.
Please follow the instructions below:
1. Always backup your Firefox 12 (or lower) folder.
2. Download the installer for Firefox 13+.
3. The installer will deliberately refuse to install on Windows XP SP1 and below with the error message, "Sorry, Firefox can't be installed. This version of Firefox requires Microsoft Windows XP SP2 or higher". To get around this, you need to extract it using a ZIP utility such as 7-Zip.
4. Copy the contents of the "core" folder to the "Firefox" directory.
5. In order to get Firefox working, you need to download the latest version of Known DLL Wrappers/Force Compatibility (KDW/FCWin2k) utility, unpack it and copy the hacked uxtheme.dll file to the "Firefox" directory. Using the uxtheme.dll from a Windows XP installation will not work as it uses a bunch of dependencies that do not exist on Win2k.
6. Download and install the latest version of the Unofficial Updates Rollup (UURollup).
7. Reboot your computer for the changes to take effect. This is very important as you will run into dependency problems when using some of the features working on Win2k.
8. After you reboot, you can now run the latest version of Firefox!
9. When you run the latest version of Firefox on Win2k, you MUST disable "Hardware Acceleration" in Tools > Options > Advanced > General. If you don't do this, you will likely see strange graphical glitches on the screen that will cause the browser to not work correctly. This is recommended prior to installing Firefox 13 on Win2k.</ol>That's about it for now. Additional detailed explanations is that you will need a unofficial kernel extension (such as BWC or WB) and the Microsoft Visual C++ 2010 libraries to run applications compiled using Visual Studio 2010. The unofficial kernel and the libraries associated with it are included in the UURollup itself. Dependency problems that causes incompatibility issues on Win2k are fixed in it.
Be advised that by doing this, YOU'RE ON YOUR OWN. The workarounds that I provided above are NOT supported by Mozilla and you must USE THE NEWER SOFTWARE AT YOUR OWN RISK!