Hi,
If planning to install SEP 12.1 RU2 then need to look at the following workaround to install it successfully
1) Disable Windows Defender before installing the SEP client
2) Remove KB2781197 before installing the SEP client
Reference: Symantec Endpoint Protection client fails to install to recently updated Windows 8 computers
http://www.symantec.com/docs/TECH203996
SEP 12.1 RU3 has a fix for this issue.
After applying Microsoft update KB2781197 to a Windows 8 computer, the Symantec Endpoint Protection client installer fails
Fix ID: 3123310
Symptom: The following lines are from the SEP_INST.log generated from a failed installation attempt:
(SERVER) MSI (s) (04:18) [08:56:49:093]: Executing op: CustomActionSchedule(Action=ShowServiceProgress,ActionType=3073,Source=BinaryData,Target=ShowServiceProgress,CustomActionData={3771A34D-2132-48EA-A486-D62ECDF9D553};SOFTWARE\Symantec\Symantec Endpoint Protection;Executing install script via service;)
(SERVER) MSI (s) (04:5C) [08:56:49:250]: Invoking remote custom action. DLL: C:\WINDOWS\Installer\MSI6B0.tmp, Entrypoint: ShowServiceProgress
(UNKNOWN) ScriptGen: ShowServiceProgress() MSIRUNMODE_SCHEDULED
(UNKNOWN) ScriptGen: ShowServiceProgress() calling WaitForSingleObject(scriptStarted) ...
(UNKNOWN) ScriptGen: ShowServiceProgress() WaitForSingleObject(scriptStarted) returned WAIT_OBJECT_0
(UNKNOWN) ScriptGen: ShowServiceProgress() script execution failed.
(UNKNOWN) ScriptGen: ShowServiceProgress() reset script failure event.
(UNKNOWN) ScriptGen: ShowServiceProgress() is returning an error
(UNKNOWN) CustomAction ShowServiceProgress returned actual error code 1603
Solution: For installations on Windows 8, removed the option to enable/disable Windows Defender after install, as this is no longer supported. Windows Security Center (WSC) will automatically disable Windows Defender when Symantec Endpoint Protection registers with WSC.
Reference: New fixes and features in Symantec Endpoint Protection 12.1.3