CIPC 8.6.x works on – not officially supported on Windows 10/11. On newer Windows, use compatibility mode.
If you find a CiscoIPCommunicator8660.exe file on a third-party website, you should proceed with extreme caution. Many of these files are either: cisco ip communicator 8.6.6.0 download
Many users find CIPC no longer listed. Cisco removed it after EOL. CIPC 8
Since CIPC is dead, consider these Cisco softphones instead: consider upgrading to supported Cisco clients:
If you are not constrained by legacy CUCM (versions 8.x or older), consider upgrading to supported Cisco clients: