The silent upgrade to 11.5 or R12 may sometimes fail on Window. No log is produced in install directory.
Release : 12.0
Component : CA Workload Automation System Agent
The upgrade properties file has hidden UNICODE characters.
Use type command in command prompt to see the properties file.
D:\installers>type win_installer.properties | more
#===============================================================#
# SILENT INSTALLER PROPERTIES FILE #
# #
# For installing the WA Agent 12.0.00.00 #
# in silent mode #
Use Notepad++ or Wordpad to edit the properties file. In Notepad++ use "Encode in UTF-8 without BOM" to edit and save the properties file.