Check if you have UAC on or an anti virus progam that is disallowing the renaming action.
Also did you set the properties on the file with which you start FH2. Tried different compability modes ?
Do you have the retail version or the download version of BF2.
If all that fails, delete all folders in the Libraries/documents/battlefield 2/mods folder, start BF2 - run a multiplayer game. Disconnect properly form the server. Exit BF2. Start FH2. Join Multiplayer game. Keep fingers crossed.
When you receive an error, make a screenshot of it.