This was originally posted by KestrelHawk[ÐÐ]
Modified June 08 by: MWO_Tek-BK-

This can also be used to change your name without losing your rank.

Where the files are located:

Assuming your Windows user name is William, and your player name is BillyTheKid

WinXP
C:\Documents and Settings\William\Local Settings\Application Data\Activision\CoDWaW\players\profiles\BillyTheKid

Vista
C:\Users\William\App Data\Local\Activision\CoDWaW\players\profiles\BillyTheKid

Windows 7/8/8.1
In the search window type in %appdata% and hit enter.
When the window opens, click on AppData in the address bar. Then click on Local – Activision – CoDWaW – players – profiles – BillyTheKid

These three files are the important ones.

config.cfg
config_mp.cfg
mpdata


If you play single player, there is also a folder called save with your savegames (optional).

To back up your profile:
1) Exit the game.
2) Back up these three files to a separate folder, keep multiple copies if necessary.

To change your name and keep your rank.

1) Back up your files (above).

2) In game, create a new profile with your new name.

3) Once step 2 is complete, exit the game.
Copy the three important files from your CURRENT profile to your NEW one.
You will overwrite the ones there already.
If you do this backwards, you will erase your current rank, and unless you followed Step 1, you are out of luck.

4) Rejoice! Now you have two profiles with the same rank, and two different names.

5) Delete the old profile (only if you want to, you don't have to).

Yep, I have 4 profiles