Symptoms

Mac freezes during the startup process.

Cause

This malfunction is caused by the issue in the updated Apple Installer application.

Resolution

To solve the problem please do the following:

   1. Restart your Mac.
   2. Hold down Command + S to boot in the Single mode.
   3. Type the command below and press Enter:
             mount -uw /
   4. Type the command below and press Enter:
             chmod 1775 /Volumes/<Your Leopard volume>
   5. Press Ctrl+D or type exit.

After that Mac will load properly. You can continue the process of Parallels Desktop for Mac build 3.0 installation. The issue will be fixed in the future versions of Parallels Desktop for Mac.