okay, I downloaded it today onto Window XP. I extracted it to my downloads but when I tried to open the file, it came up with a black screen and said:

"You have reached this menu because of missing or unlocatable data.

You may consider adding
-basedir /path/to/game
to lauch your comand line"

Then it gives me the option to open a little window thing with all this computer text or Exit.


HEEEEEEEEEEEEEEEELLLLLLLLLLP D:

Looks like you haven't extracted the .zip properly as the engine can't find all of the data files. It should give you a Nexuiz directory within which you will find several sub directories as well as the executable files and some libraries. What is the file structure of the Nexuiz directory that you have?

Another thing: Writing HEEEEEEEEEEEEEEEEEEEEEEELLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP generally isn't the best way of getting help on forums.

I've tried re-extracting it but it still wont work. An interesting note though, when I extract it, it says "Bad Zip Header found. Continue anyway?" I just said yes :/. Cause of problem maybe?

Propably. To avoid downloading the whole thing again I suggest to download via torrent.
Just after starting the download with your torrent client, stop it and copy your corrupted zip file over the file your torrent client is downloading. After that have your torrent client recheck the downloaded file and than you can continue downloading. That should get only the broken/missing parts and should be done in a matter of seconds.

EDIT: torrent link: http://morfar.affro.net/nexuiz/torrents/nexuiz-252.zip.torrent