Hello,
Since you are running SEP 11.x, here are the steps -
To reset the administrator password
- Open Windows Explorer on the computer that runs Symantec Endpoint Protection Manager.
- Locate the Drive:\Program Files\Symantec\Symantec Endpoint Protection Manager\Tools folder.
- Double-click resetpass.bat.
The user name and password are reset to admin.
- Log on to Symantec Endpoint Protection Manager using admin for both the user name and the password, and change the password.
Check this Article:
Resetting the administrator password to admin
http://www.symantec.com/docs/HOWTO18134
Hope that helps!!