Certain versions of Quake 2 show the error - "This version of Quake II will not install on this language version of windows 95/NT" when installing in Windows XP.
This problem can be fixed by following these steps:
1. Control Panel > Date, Time, Language and Regional Options > Regional and Language Options
2. In the Standards and Formats section, select English (United Kingdom)
3. Change the location as United Kingdom
4. Now click on the Advanced tab
5. In the "Language for non-Unicode programs" section, select English (United Kingdom)
6. If you need install the files, do so using your Windows XP CD. If you don't have to, then save the settings and restart your computer.
Now you should be able to install Quake 2 without any problem. If you want to revert back to the original settings, you can do so after installing the game.