Go to start run and Type %temp%

Look for SEP_Inst.log
 and search for Return vaule 3 and paste 5-6 lines before and after that

Action 15:58:25: InstallLiveUpdate.FF07F38E_78C2_412E_B858_64488E808644.
MSI (s) (5C:94) [15:58:25:298]: Executing op: CustomActionSchedule(Action=InstallLiveUpdate.FF07F38E_78C2_412E_B858_64488E808644,ActionType=3073,Source=BinaryData,Target=InstallLiveUpdate,CustomActionData=C:\DOCUME~1\RECEPT~1\LOCALS~1\Temp\WTJIXYXX\LiveUpdate\lucheck.exe)
MSI (s) (5C:C4) [15:58:25:298]: Invoking remote custom action. DLL: C:\WINDOWS\Installer\MSI1D8.tmp, Entrypoint: InstallLiveUpdate
LUCA: InstallLiveUpdate enter.
LUCA: C:\DOCUME~1\RECEPT~1\LOCALS~1\Temp\WTJIXYXX\LiveUpdate\lucheck.exe
LUCA: InstallLiveUpdate : CreateProcessAndWait( LUCHECK.EXE ) returned 100
Action ended 15:58:28: InstallFinalize. Return value 3.
MSI (s) (5C:94) [15:58:28:083]: User policy value 'DisableRollback' is 0
MSI (s) (5C:94) [15:58:28:083]: Machine policy value 'DisableRollback' is 0
MSI (s) (5C:94) [15:58:28:099]: Executing op: Header(Signature=1397708873,Version=301,Timestamp=993165127,LangId=1033,Platform=0,ScriptType=2,ScriptMajorVersion=21,ScriptMinorVersion=4,ScriptAttributes=1)
MSI (s) (5C:94) [15:58:28:099]: Executing op: DialogInfo(Type=0,Argument=1033)
MSI (s) (5C:94) [15:58:28:099]: Executing op: DialogInfo(Type=1,Argument=Symantec Endpoint Protection)
MSI (s) (5C:94) [15:58:28:099]: Executing op: RollbackInfo(,RollbackAction=Rollback,RollbackDescription=Rolling back action:,RollbackTemplate=[1],CleanupAction=RollbackCleanup,CleanupDescription=Removing backup files,CleanupTemplate=File: [1])
Action 15:58:28: Rollback. Rolling back action:

LUCA: InstallLiveUpdate enter.
LUCA: C:\DOCUME~1\RECEPT~1\LOCALS~1\Temp\WTJIXYXX\LiveUpdate\lucheck.exe
LUCA: InstallLiveUpdate : CreateProcessAndWait( LUCHECK.EXE ) returned 100

Try the steps in sequence:

1. Uninstall LU if it is there in addremove Programs

2. Delete the following folders (if they exist):

C:\Program Files\Symantec

C:\Program Files\Symantec Antivirus

C:\Documents and Settings\All Users\Application Data\Symantec\LiveUpdate

4. Shut down the Windows Installer service and then re-register

Click Start, and then click Run.

In the Open box, type msiexec /unreg, and then click OK

When this process is complete, click Start, and then click Run.

In the Open box, type msiexec /regserver, and then click OK

5. Reboot the machine

Then INSATALL SEP

3. Check the DCOM settings:

http://service1.symantec.com/SUPPORT/ent-security.nsf/docid/2002103013521548

Tried all steps listed and got the same result. Any other processes to try?

Please paste the new  SEP_Inst.log

: Executing op: CustomActionSchedule(Action=InstallLiveUpdate_RB.FF07F38E_78C2_412E_B858_64488E808644,ActionType=3329,Source=BinaryData,Target=UnInstallLiveUpdate,CustomActionData=C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\EHWIJUKW\LiveUpdate\lucheck.exe)
MSI (s) (24:E4) [11:55:04:920]: Executing op: ActionStart(Name=InstallLiveUpdate.FF07F38E_78C2_412E_B858_64488E808644,,)
Action 11:55:04: InstallLiveUpdate.FF07F38E_78C2_412E_B858_64488E808644.
MSI (s) (24:E4) [11:55:04:920]: Executing op: CustomActionSchedule(Action=InstallLiveUpdate.FF07F38E_78C2_412E_B858_64488E808644,ActionType=3073,Source=BinaryData,Target=InstallLiveUpdate,CustomActionData=C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\EHWIJUKW\LiveUpdate\lucheck.exe)
MSI (s) (24:94) [11:55:04:951]: Invoking remote custom action. DLL: C:\WINDOWS\Installer\MSI109.tmp, Entrypoint: InstallLiveUpdate
LUCA: InstallLiveUpdate enter.
LUCA: C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\EHWIJUKW\LiveUpdate\lucheck.exe
LUCA: InstallLiveUpdate : CreateProcessAndWait( LUCHECK.EXE ) returned 100
Action ended 11:55:08: InstallFinalize. Return value 3.
MSI (s) (24:E4) [11:55:08:203]: User policy value 'DisableRollback' is 0
MSI (s) (24:E4) [11:55:08:203]: Machine policy value 'DisableRollback' is 0
MSI (s) (24:E4) [11:55:08:219]: Executing op: Header(Signature=1397708873,Version=301,Timestamp=993484508,LangId=1033,Platform=0,ScriptType=2,ScriptMajorVersion=21,ScriptMinorVersion=4,ScriptAttributes=1)
MSI (s) (24:E4) [11:55:08:219]: Executing op: DialogInfo(Type=0,Argument=1033)
MSI (s) (24:E4) [11:55:08:219]: Executing op: DialogInfo(Type=1,Argument=Symantec Endpoint Protection)
MSI (s) (24:E4) [11:55:08:219]: Executing op: RollbackInfo(,RollbackAction=Rollback,RollbackDescription=Rolling back action:,RollbackTemplate=[1],CleanupAction=RollbackCleanup,CleanupDescription=Removing backup files,CleanupTemplate=File: [1])
Action 11:55:08: Rollback. Rolling back action:

What is the version of LU .

If its is 3.3 it OK
Then try this

http://service1.symantec.com/SUPPORT/ent-security.nsf/docid/2007073018014248

I have the exact same problem with a lot of terminal servers that's already running SEP 11. I'm try to upgrade them to the latest SEP version but also get the above error.

Windows Installer Clean Up Utility from Microsoft can help out.  This utility will not uninstall Symantec, but it will remove registry information associated with the program.  It can be downloaded here.

Once it is installed run the program and then select the program you want to remove from your system (if it won't uninstall properly).  Then Click Remove.