I'm not familiar with the Teamfortess mod but generally
you could do the following if you were using a Quake engine like Proquake, Qrack, EngineX, and presumably MarkV (Baker?):
- create a directory under quake, lets call it tf.
- Copy your mod files in to your tf directory as directed.
- Make a copy of your batch script, presuming you have one, that you would normally use to run quake. lets call it tf.bat
- Edit tf.bat and remove any references that may be in the quake command line to "-game SomeModName",
- add -game tf to the quake command line and save the tf.bat script
- run your tf.bat script
If all has gone well your tf.bat script should fire up quake and also run the mod. Please bare in mind that some mods require you to add a +map SomeMapName
to the command line to ensure you start at the desired map.
Hope this helps