Hello,
Symantec Endpoint Protection 11.0.5002 was the first version which supported the Windows 7 version.
I would request you to Install the Latest version of Symantec Endpoint Protection version 11.0.7101 on your Windows 7 64 bit machine.
Support for Symantec Endpoint Protection on Microsoft Windows 7
http://www.symantec.com/docs/TECH91247
About Endpoint Protection support for Windows 7 and Windows Server 2008 R2
http://www.symantec.com/docs/TECH94910
I am sure that would work.