While upgrading Plesk, autoinstaller shows the following error:
ERROR: The installation of the package 'xxxxx' failed with code 1603.
MSI package of an already-installed component is not present on the server.
Download the missing MSI package for Plesk 11.5 from http://autoinstall-win.plesk.com
Move it to
C:\\ParallelsInstaller\\parallels\\PANEL-WIN_11.5.30\\dist-msiWindows-2003-i386\\on the server.
Re-run the upgrade: