Sometimes after repeated installs and patches of Doom 3 your folder structure can get a little messy and even lead to problems running the game. People often attempt multiple uninstalls / reinstalls and still things don't work. This tutorial is a manual cleanup procedure for when nothing else seems to work and should completely remove all traces of Doom 3 giving you a clean platform to reinstall on.
Do this as you would normally do for any program using either the Add/Remove programs Control Panel applet or using the Uninstall option from the Doom 3 CD. If you have installed the "DOOM 3 Resurrection of Evil" expansion pack you should uninstall that too.
The Doom 3 1.3 patch will sometimes refuse to reinstall after it has been used once. This can be resolved using the Windows Installer CleanUp Utility. Note that Microsoft have now withdrawn this utility; you can read about that here. Install the utility and run it (the icon for it gets put directly on the "Start / Program Files" menu) and you'll see something like this:
Select all Doom 3 related items and click "Remove". Note that this does not delete the programs from the system it just removes them from the Windows Installer database.
The uninstall programs may have left some Doom 3 related registry entries behind. If you're planning to do a complete reinstall it is worth removing these.
Use your favourite text editor (Notepad is fine) and create a file with the following three lines and save it to your hard disk as Doom3Remove.reg. Note that the first character after the opening sqaure bracked is the minus sign; this instructs the system to delete the specified registry key. You can download a pre-created version of the file from here if you wish.
Windows Registry Editor Version 5.00
[-HKEY_LOCAL_MACHINE\SOFTWARE\id\Doom 3 Resurrection of Evil]
Using Windows Explorer double-click on Doom3Remove.reg. You will be asked the following security question...
...to which you should reply "Yes". The Doom 3 registry entries will then be removed and you'll get a confirmation message:
All that is left to do is clean up the "Doom 3" folder. If you've installed mods or have downloaded custom maps from servers you may still have quite a few files here. You can just delete the "Doom 3" folder completely if you wish but I would recommend that you simply rename it to "Doom 3.old" so that you still have any map files you may want.
Now you can do a reinstall of Doom 3.
After you've reinstalled there are two main patch versions in use. Version 1.3 (1302) is the version that most SP mods have been created for. There are fewer online servers running this version.
Version 1.3.1 (1304) has been around a couple of years now and most online servers run this version. Most MP mods have moved to this version; ourselves here at EMZ, OpenCoop, 5.56mm Full Metal Jacket and the next Last Man Standing will be 1.3.1 compatible.
You may wish to consider having a dual install of both versions to allow you to access all servers and mods. There is a separate tutorial on this site for helping set that up.