Okay. This is interesting. I can't edit my post. Can someone stick the following post in its place?
How to install FS2_Open on top of the 3 CD download
First thing you should do is install FS2. Do a full install (or else you may have problems with the 1024x768 resolution modes).
Then you'll need to download these two files
Launcher 5.4
and
3.6.9 Release Candidate 7.8
Extract both files to your Freespace 2 folder.
Now you'll need the media VPs. To be honest they're actually optional but without them you won't get any of the new ship models or graphics so there is little point in updating to FSO. Go to
this thread. What you need is mv_zpack (which is a big file containing the most important media VP files) and the 710 patch files. Download these, create a new folder within your main freespace folder called media VPs and extract them to there.
I suggest you leave mv_adveffects alone for now. If you have a really powerful computer you can go back and try it out once you're certain everything works.
Now go
here, download and run the OpenAL installer.
That's everything downloaded that you need. Time to set up. Go into your FS2 folder and run the launcher. Click the browse button at the top and choose fs2_open_3_6_9.exe.
Go to the features tab and turn on the first 5 graphics options. You can experiment quite safely with the Audio, HUD, Game Speed and Gameplay options but you probably should leave anything else alone.
Now go to the video tab and select OpenGL if it isn't already selected. D3D support is virtually non-existant and you will almost certainly have problems running in D3D so you should only use it as a last resort.
Set up the audio/joystick and network tabs while you're here.
Lastly go to the mod tab and select mediavps as your mod. This step enables the mediavps. If your PC runs the game too slowly come back here and click no mods. You'll lose the new graphics etc but you'll be able to play the game with the original files this way and that should be faster..
Press run. Enjoy the game.