Hi,
Symantec Endpoint Protection (SEP) adds support for Windows 10 with 12.1.6 MP1.For Symantec Endpoint Protection 12.1, a maintenance patch has been released on July 29, 201
Client only patch is also available to make SEP compatible with Windows 10. These Symantec Endpoint Protection (SEP) client-only patches allow you to upgrade a client from older versions of SEP to SEP 12.1.6.
Symantec Endpoint Protection 12.1.6 client-only patches
http://www.symantec.com/docs/INFO2684
To upgrade more than one client, or to upgrade Symantec Endpoint Protection Manager, download the full installer.
To know more details about Windows 10 compatibility, check the following article:
http://www.symantec.com/docs/INFO2746