How can I completely uninstall/delete/remove Quake 3 Arena from my PC?

Now I like this game, but for some reason the bots will not use any weapons but the gauntlet and the BFG. It did not start like this. I had been playing the game and joined a random game online and downloaded something that does that I suppose. However I look in my mods and none of the mods are for that. I have "berryllium" and "excessive". So I have tried to remove the game many times and when I install again it is exactly the same.