How to get Call Of Duty 4 to work with STEAM:
Step 1
Download all the follwing files listed below then continue to step 2:
http://cs.rin.ru/forum/CFToolbox/CFToolbox.zip <-------CTFToolBox.
http://www.linksafe.ws/files/yy98-86091-5/ <-----Entire COD4 Files needed "note if you already have COD4 installed on your PC you can just C+P the entire folder minus the player folder into your "C:\Program Files\Steam\steamapps\common" folder".
http://rapidshare.com/files/88462915/call_of_duty_4_modern_warfare_content.6_to_10.update.rar <-------Needed to get your STEAM COD4 files up to date.
http://rapidshare.com/files/88462925/call_of_duty_4_modern_warfare_english_public.4_to_7.update.rar <-------Needed to get your STEAM COD4 files up to date.
http://campstaff.cheat-project.com/p/UnDeadPatch.exe <------Needed to patch STEAM to enable all games.
http://rapidshare.com/files/90370221/cod4.ncf-rin.rar.html <--------COD4 NCF Files needed to allow COD4 in steam.
http://files.filefront.com/cod4zip/;9617224;/fileinfo.html <------Registry entry.
Step 2
Once you have all these files downloaded just store them away in a location where all of them are together if you wish to just keep track of them all.
Okay first things first, if you DONT have an already installed copy of COD4, you will need to download all the different files provided to you in step one, there should maybe be like 20+ folders once thats done you can really get started with the rest of the process you will need all these COD4 files to get the game to work correctly.
Next you want to take the COD4 NCF fiiles there should be 7 in all take all 7 files and drag or paste them in C:\Program Files\Steam\steamapps folder then once that is done drag the UnDeadPatch into your steam directory "C:\Program Files\Steam" and execute it, this is where you can choose for yourself yes/no it doesnt really matter. Once this is done run the CTFTool and locate it to where yor NCF/CGF files are located "usually" C:\Program Files\Steam\steamapps, once you have done this you should see files on the program list that should say "outdated" to the right of them.
This is where you right click the files and go to "update-apply update" when it brings up the dialog box search for the 2 files you downloaded that are labeld "call_of_duty_4_modern_warfare_content.6_to_10.update/call_of_duty_4_modern_warfare_english_public.4_to_7.update" make sure you unrar these files first so you can find them wherever you unrared them once this is done it should say to the right of them now "File Updated" once you see this status on both files exit out of the CTFTool.
Step 3
Once you have done whats all above you should be near completion now all these file folders you have downloaded for COD4 like 20+ folders containing the needed Call Of Duty 4 steam files, C+P them all into your "C:\Program Files\Steam\steamapps\common" folder, if you already have COD4 installed by CD all you really need to do is C+P your entire COD4 directory into the same location, now the 20+ rared folders provided I do not know if they are "up 2 date" so you may once you C+P all these files into the steam folder and run steam you may need to update to the newest version.
Once you have done what was said above, now take the registry file and add it to the registry and I "believe" this is all you need to do. If you find this works and COD4 starts BUT DOES not go to the main screen go to your C:\Program Files\Steam\steamapps\common folder and look for "profile" folder and delete that folder then you should be okay and it SHOULD load up just fine