CME 4.3 basic system files for IOS 12.4(15)XZ releases, includes GUI files and Basic Phone Loads (7906/11, 7921, 7937, 7941/61). Certain Software Downloads/Upgrades from Cisco requires Additional access/Valid Service contract. Availing this contract would gives you access to most of the tools and to the Encrypted Software's.
The following URL will help you to get information. To open this link you have to give your CCO username and password.
http://www.cisco.com/cgi-bin/Software/Tablebuild/doftp.pl?ftpfile=cisco/voice/ip-phone/ip-iostsp/cme-basic-4.3.0.0.tar&app=Tablebuild&status=showC2A