You may have multiple accounts on your machine.
In the instructions the part about the general.con, this link: ...Documents\Battlefield 2142\Profiles\0001\ is just an example.
If your game was already installed from long ago the you could have multiple profile folders like 002, 003, 004 etc.
You could just replace the general.con in all the profile folders or check the Profile.con in each folder to find your user name.
Hope this helps.