Hi,
Thank you for posting your query on Symantec community.
Symantec Endpoint Protection (SEP) adds support for Windows 10 with 12.1.6 MP1 (12.1.6306.6100). For Symantec Endpoint Protection 12.1, a maintenance patch has been released on July 29, 2015.
http://www.symantec.com/docs/INFO2746
Either upgrade the SEP client or uninstall existing version using latest Cleanwipe tool. Latest Cleanwipe tool can remove SEP thought it's password protected. If you do not have an accesss to download tool from fileconnect get in touch with your company admin.
or last resort to perform manual removal steps outlined here:http://www.symantec.com/docs/TECH96924 .