Unable to install the IP Communicator on Microsoft Windows Vista, and a message appears which states that XP Service Pack 1 or later is required.
In order to use the IP Communicator on Windows Vista, the IP Communicator version must be 2.1(1) or later.
Refer to Release Notes for Cisco IP Communicator Release 2.1 for more information.
IP phones and other clients (Client registration, faulty IP phone, etc.)
Common Software and Product Issues
IP Phone Software