Hello,
None of the Symantec Endpoint Protection version 11.x is supporting Windows 8 at this time.
Support for Windows 8 and Windows Server 2012 is introduced with the release of SEP 12.1 Release Update 2. SEP 12.1 RU2 is the earliest supported build which is compatable with Windows 8 and Server 2012.
Earlier releases of SEP 12.1 offer support for computers running Windows 7, Windows 2008, WES7 and other Operating Systems.
Reference:
About Windows 8 and Symantec Endpoint Protection 12.1
http://www.symantec.com/docs/TECH174348
In case if you are thinking of Migration to Symantec Endpoint Protection 12.1 RU2, here is the Article:
Best practices for upgrading to Symantec Endpoint Protection 12.1.2
http://www.symantec.com/docs/TECH163700
and
Knowledgebase Articles for Symantec Endpoint Protection 12.1. RU2
Hope that helps!!