Also if you are using SEP 11.0.5002 then you need to follow this

Windows 7 / 2008 R2 - SEP Client installation rolls back

http://service1.symantec.com/SUPPORT/ent-security....

Work around for issue:

1. Open and log into Symantec Endpoint Protection Manager
2. Select Admin
3. Select the 11.0.5002.0 package you wish to deploy (either WIN32BIT or WIN64BIT)
4. Click on Export Client Install Package
5. Enter the folder location for the client package
6. Uncheck the box for create a single .EXE file for this package.
7. Select Settings and Features desired and Policy settings and Mode and click on OK
8. After the package has finished exporting open the Symantec_Endpoint_Protection_11.0.5002.333_RU5 CD 1\SEP directory and copy the LuCheck.exe and LUSETUP.EXE in to the folder where expanded package was exported overwriting the existing LuCheck.exe and LUSETUP.EXE.
9. The package can then be deployed via the Migration and Deployment Wizard

This will need to be done for both the 32bit and 64bit clients.