64 bit version running nice here on 7 pro

are tehre any other errors? IIRC there is an install log.

I know I have had issues with some installs.  Is this a migration from another AV client?  In some cases, I have uninstalled LiveUpdate manually then installed SEP with success.

Also there are times I see in the SEPINST.log "Pending reboot required".  I'll reboot, then the client installs fine.

Hope this helps.

Is this the first time you tried to install on 7 on this machine?

This is the 1st  thru the 7th time I've tried installing on this machine. 
There is no other AV installed on this machine.  I t is a newly built W7 machine.
Not pending any reboots.

To install  SEP try these steps

        Run SETUP.EXE to install Symantec Endpoint Protection.

Copy the contents of the Symantec Endpoint Protection folder to your local hard drive or a network share.

Run LUSETUP.EXE to install LiveUpdate.

Restart the computer.

1.)   ran SETUP.EXE     2.) Copeind the Symantec Endpoint Protection folder to C: drive   3.) ran LUSETUP.EXE   4.) restarted the computer       The installation of Endpoint  on this machine with W7 again stops with the same EVENTID 1033 error

Hello DMPE
Open regedit and navigate to HKLM\SYSTEM\CurrentControlSet\Control\SessionManager\
and delete  PendingFileRenameOperations after that install your sep again. without restart
Thanks
Fatih

Thanks Faith for the suggestion, however there is no 'PendingFileRenameOperations' to delete.  I've searched the entire Registry.

is this managed client or unmanaged? and is this install package slient? or you can see install? what will happend is it roll back?
Thanks
Fatih

Can you please paste the SEP_Inst.log

Go to run and type %temp% and then you can acess the logs

 open the file search for return value 3 ( the first one)
then copy 10-15 lines above the return vlaue 3 and paste it over here.

or 
If you edit your original post ( the main question) then on the bottom you will find a attachment button.

 Did this computer come with Norton Antivirus ?
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Norton AntiVirus Corporate Edition

If yes then download and run norton removal tool once
http://service1.symantec.com/Support/tsgeninfo.nsf/docid/2005033108162039

 Hope someday these softwares and operating systems work as expected...

I am installing it on a new Windows 7 Pro (32bit) computer that has only previously had MS Security Essentials running on it. MSE was removed and I rebooted. The SEP install rolls back.
I have rebooted and retried the installation, but they just keep rolling back.

I assume that MR5 supports Proactive Threat & Network Threat features? I have read elsewhere that these don't work on W7, but I think that was on earlier versions of SEP.

Any ideas why it's failing?

Below is the sep_inst.log. I have pasted in the lines after "return value 3".

Action ended 14:49:31: InstallFinalize. Return value 3.
MSI (s) (DC:C0) [14:49:31:222]: Executing op: Header(Signature=1397708873,Version=500,Timestamp=997750294,LangId=1033,Platform=0,ScriptType=2,ScriptMajorVersion=21,ScriptMinorVersion=4,ScriptAttributes=1)
MSI (s) (DC:C0) [14:49:31:222]: Executing op: DialogInfo(Type=0,Argument=1033)
MSI (s) (DC:C0) [14:49:31:222]: Executing op: DialogInfo(Type=1,Argument=Symantec Endpoint Protection)
MSI (s) (DC:C0) [14:49:31:237]: Executing op: RollbackInfo(,RollbackAction=Rollback,RollbackDescription=Rolling back action:,RollbackTemplate=[1],CleanupAction=RollbackCleanup,CleanupDescription=Removing backup files,CleanupTemplate=File: [1])
MSI (s) (DC:C0) [14:49:31:237]: Executing op: ActionStart(Name=LU_Register_Decomposer_ABI.611D9A69_39FC_4998_998E_1ECADF28A979,,)
MSI (s) (DC:C0) [14:49:31:237]: Executing op: ProductInfo(ProductKey={2E2966EA-2169-4E42-8A8A-CC1749D80088},ProductName=Symantec Endpoint Protection,PackageName=Symantec AntiVirus.msi,Language=1033,Version=184551386,Assignment=1,ObsoleteArg=0,ProductIcon=ARPPRODUCTICON.exe,,PackageCode={A6726214-4E90-4B1D-9A27-748FCDEC6BAC},,,InstanceType=0,LUASetting=0,RemoteURTInstalls=0,ProductDeploymentFlags=3)
MSI (s) (DC:C0) [14:49:31:237]: Executing op: ActionStart(Name=LU_Register_Decomposer_ABI.Rol.611D9A69_39FC_4998_998E_1ECADF28A979,,)
MSI (s) (DC:C0) [14:49:31:237]: Executing op: CustomActionRollback(Action=LU_Register_Decomposer_ABI.Rol.611D9A69_39FC_4998_998E_1ECADF28A979,ActionType=1281,Source=BinaryData,Target=_LURollbackDecomposerABI@4,CustomActionData=not installed:not installed)
MSI (s) (DC:AC) [14:49:31:237]: Invoking remote custom action. DLL: C:\Windows\Installer\MSI8143.tmp, Entrypoint: _LURollbackDecomposerABI@4
-- DECABI_LOGGING --   Enter LURollbackDecomposerABI()
-- DECABI_LOGGING --   Decomposer ABI Rollback property version = not installed
-- DECABI_LOGGING --   Decomposer ABI Rollback property sequence_number = not installed
-- DECABI_LOGGING --   Rollback of LiveUpdate un-registration failed. (HRESULT=-2147221164)
MSI (s) (DC:C0) [14:49:31:237]: Executing op: ActionStart(Name=MSIAddWFPAppException_RB.1CBEC0D3_E547_4E51_828B_44B9C47C0EA5,,)
MSI (s) (DC:C0) [14:49:31:237]: Executing op: CustomActionRollback(Action=MSIAddWFPAppException_RB.1CBEC0D3_E547_4E51_828B_44B9C47C0EA5,ActionType=3329,Source=BinaryData,Target=MSIRemoveWFPAppException,CustomActionData=SMC Service;C:\Program Files\Symantec\Symantec Endpoint Protection\Smc.exe;SNAC Service;C:\Program Files\Symantec\Symantec Endpoint Protection\SNAC.EXE;Symantec Email;C:\Program Files\Common Files\Symantec Shared\ccApp.exe;)
MSI (s) (DC:B4) [14:49:31:237]: Invoking remote custom action. DLL: C:\Windows\Installer\MSI8144.tmp, Entrypoint: MSIRemoveWFPAppException

  Rollback of LiveUpdate un-registration failed. (HRESULT=-2147221164)

You should open a new discussion for your issues however.Your issue is diffrent
Install Liveupdate reboot your computer then install SEP.

From wherver you are installing if from CD then Cd1\SEP\lusetup.exe if from package then lusetup.exe from that
Run Lusetup.exe to install Liveupdate reboot then install SEP.