You need an archive manager. WinRAR and 7zip both work. Once you get the files extracted into a new folder, go into the "Update" folder and run "Update.exe" to start installation. For the January 3rd release, it will complain about shell32.dll being in use. You'll need to open Task Manager and stop the explorer.exe process, then click retry, and installation should continue as normal.
Download the full version of the Firefox setup.exe file. Don't download the "stub" that downloads the rest of the setup files when you run it. That won't work on Windows 2000.
When you get Unofficial Update Rollup installed, you'll notice a new programme in the start menu under accessories. "Application Compatibility Launcher". You'll use it to run setup.exe files, basically fooling them into thinking they're running on Windows XP, allowing you to install the software, that otherwise would refuse to install. You'll open the Application Compatibility Launcher programme (which will be a command prompt window), then you'll drag and drop the setup.exe file for any given programme (say Firefox) into the window and press Return/Enter on the keyboard. Then setup should run as normal. When finished you can choose whether or not to save the compatibility settings for that particular file. "Yes" or "no". I usually choose no.
Unofficial 2010 release of DirectX 9.0c ported from Windows XP. Windows 2000's version of DirectX 9.0c is apparently outdated, and fellow forum user BlackWingCat decided to port the 2010 release of DirectX for Windows XP to Windows 2000, to enable Windows 2000 to play some games that require the newer version of DirectX. One example game being Rigs of Rods.
You can download it here. Install it after Unofficial Update Rollup: http://www.mediafire...Jun2010w2kb.exe
I hope that all made sense. If you have any more questions, leave them here and I'll answer them in the morning. For now, I'm going to sleep.