:\Documents and Settings\****insert your account name here****\Local Settings\Application Data\Activision
this is where ya CoD5 player profile is saved along with ya rank and save games if you copy/backup this you can restore it at a later time say after a format or some other disaster and you will retain your settings rank everything
*NOTE* if you cant see the folder im talking about you will need to turn off windows hidden folders ect... Folow these intructions
1.open windows explorer select "Folder Options" From the "Tools" menu
2.Select the "View" tab
3.Place a check in the box "Display Contents of System Folders"
4.Place a check in the Circle "Show Hidden Files and Folders"
5.Uncheck "Hide Extensions for Known File Types"
Now go back to the top and try again