Version 1.3.1

Multiplayer 1.2 patch

Valid CD-Key: 

wygp-wde3-8k22-2uhd-17ab

Search Registry (use regedit) for CD-Key:
SOFTWARE
+Activision
++Call of Duty
+++ codkey 

value= WYGPWDE38K222UHD17AB

"INVALID INSTALLATION MESSAGE: If you get a "Setup did not detect a valid Call of Duty CD Key" error message when installing the
1.3 patch, you can try one of two things to address this issue:
1. Exit out of the patch setup and load up Call of Duty Multiplayer. In the Multiplayer Options screen, re-enter your 
Call of Duty CD key, exit the program, and then apply the patch again. 
2. If you get the error again, exit out of the 1.3 patch installer. Completely uninstall Call of Duty, 
reinstall the game, and then apply the patch.

Either one of these solutions should correct the problem."

https://activision.custhelp.com/cgi-bin/activision.cfg/php/enduser/std_adp.php?p_faqid=12263&p_created=1080068186&p_sid=X7hxlrHh&p_lva=6238&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PWRmbHQmcF9ncmlkc29ydD0mcF9yb3dfY250PTI5JnBfcHJvZHM9MSwzNjEmcF9jYXRzPSZwX3B2PTIuMzYxJnBfY3Y9JnBfc2VhcmNoX3R5cGU9YW5zd2Vycy5zZWFyY2hfbmwmcF9wYWdlPTEmcF9zZWFyY2hfdGV4dD1wYXRjaA**&p_li=&p_topview=1