Error 1069 when starting Endpoint Protection Manager service

Hello, how can I reset the 'semsrv' password? I'm getting Microsoft error 1069 "logon failure" when tryingto restart the service.

I've tried following http://www.symantec.com/business/support/index?page=content&id=TECH216042 , however cannot edit gpedit at this level. And wondering what are my other options and what would have caused this logon faliure in the first place?

Thanks.