In this situation, Cisco Unity is installed on a Windows 2000 server, and the Cisco Unity version 4.x required service pack three is installed. After the system prep utility displays the message that service pack three is required and the button to install service pack three is selected, the system is checked for hard drive space, the installation freezes.
The clue in this case is where the failure occurred, in the hard drive space. After control is passed over to the service pack installation routine, the service pack installation routing found insufficient space and stopped. This is also seen when attempting to install service pack three alone, without the Cisco Unity upgrade script running.
For a workaround to the problem, clear some hard drive space, and run the upgrade utility again.