How to Fix Battlefield 2 CD Key Error

1. Uninstall Battlefield 2 and all expansion packs. Click 'Start' and then select Control Panel. Open the Add or Remove Programs dialog box. Select all Battlefield 2 entries and remove them from your system.
2. Reinstall Battlefield 2. Patch it to version 1.41 by downloading the appropriate file from the Electronic Arts download server (see Resources). Install all expansions that you own. Run the 1.41 patch again after installing all the expansion programs.
3. Open the Registry Editor by selecting Run from the Start menu and typing in 'regedit' (without quotations). Press 'Enter.'
4. Back up the registry. Click 'File,' then 'Export.' Choose 'Export Registry' and then select All from the Export Range option. Name the file and save it to a safe location on the hard drive.
5. Browse to HKEY_LOCAL_MACHINE\SOFTWARE\Electronic Arts\EA Games\Battlefield 2\ergc on the left side of the Registry Editor window. Right-click the x9392 value on the right side of the Registry Editor. Select Modify from the pop-up menu. Enter 'x9392' (without quotes) followed by your CD key (without hyphens) as the new value. Click 'OK.'
6. Close the Registry Editor and reboot the computer to make sure that the changes take effect.