I recently had and solved this problem and I am posting the answer for reference.
I did search BF2S forums and I found pieces of this but I did not find any posts with the detail in the thread.
I found too many threads and even with a google site search of BF2S I still did not find the answer.
I found references to the C:\Program Files\EA GAMES\Battlefield 2\Support\Battlfield_code.exe
I entered the key here but it did not solve my problem
I read this post - this was the solution for me.
http://www.thehelper.net/forums/showthread.php?t=9213
This is a Registry edit to change the CD key.
The relevant part of the post is plagiarised here
If you have Battlefield 2
Click Start.
Go to Run.
Type regedit and hit OK button.
Click on plus sign next to HKEY_LOCAL_MACHINE.
Click on plus sign next to SOFTWARE.
Double click on Electronic Arts folder.
Double click on EA Games folder.
Double click on Battlefield 2 folder.
Double click on ergc folder.
Data displayed will probably have x9392 only.
Right click on it and select Modify.
Type in x9392 and then your CD key.
note: don’t include hyphens.
Example: x9392(your Battlefield 2 CD key here)
If you have Battlefield 2: Special Forces
Click Start.
Go to Run.
Type regedit and hit OK button.
Click on plus sign next to HKEY_LOCAL_MACHINE.
Click on plus sign next to SOFTWARE.
Double click on Electronic Arts folder.
Double click on EA Games folder.
Double click on Battlefield 2 folder.
Double click on ergc folder.
Data displayed will probably have x9392 only.
Right click on it and select Modify.
Type in x9392 and then your Battlefield 2 CD key.
note: don’t include hyphens.
Double click on Battlefield 2 Special Forces folder.
Double click on ergc folder.
Data displayed will probably have x9392 only.
Right click on it and select Modify.
Type in x9392 and then your Battlefield 2 CD key.
note: don’t include hyphens.
note: do not use your Battlefield 2: Special Forces CD key.
Example: x9392(your Battlefield 2 CD key here)
I hope this is useful. I hope this is not considered forum spamming.
I did search BF2S forums and I found pieces of this but I did not find any posts with the detail in the thread.
I found too many threads and even with a google site search of BF2S I still did not find the answer.
I found references to the C:\Program Files\EA GAMES\Battlefield 2\Support\Battlfield_code.exe
I entered the key here but it did not solve my problem
I read this post - this was the solution for me.
http://www.thehelper.net/forums/showthread.php?t=9213
This is a Registry edit to change the CD key.
The relevant part of the post is plagiarised here
If you have Battlefield 2
Click Start.
Go to Run.
Type regedit and hit OK button.
Click on plus sign next to HKEY_LOCAL_MACHINE.
Click on plus sign next to SOFTWARE.
Double click on Electronic Arts folder.
Double click on EA Games folder.
Double click on Battlefield 2 folder.
Double click on ergc folder.
Data displayed will probably have x9392 only.
Right click on it and select Modify.
Type in x9392 and then your CD key.
note: don’t include hyphens.
Example: x9392(your Battlefield 2 CD key here)
If you have Battlefield 2: Special Forces
Click Start.
Go to Run.
Type regedit and hit OK button.
Click on plus sign next to HKEY_LOCAL_MACHINE.
Click on plus sign next to SOFTWARE.
Double click on Electronic Arts folder.
Double click on EA Games folder.
Double click on Battlefield 2 folder.
Double click on ergc folder.
Data displayed will probably have x9392 only.
Right click on it and select Modify.
Type in x9392 and then your Battlefield 2 CD key.
note: don’t include hyphens.
Double click on Battlefield 2 Special Forces folder.
Double click on ergc folder.
Data displayed will probably have x9392 only.
Right click on it and select Modify.
Type in x9392 and then your Battlefield 2 CD key.
note: don’t include hyphens.
note: do not use your Battlefield 2: Special Forces CD key.
Example: x9392(your Battlefield 2 CD key here)
I hope this is useful. I hope this is not considered forum spamming.