Hello,
Was this working previously?
Is this the only machine having issue?
Did this issue happen upon upgrading from the earlier version of SEP 12.0.122?
I hope you are positively using SEP 12.0.1001.
The older version of SEP 12 are not compatible with Windows 7..So make sure you are using the version 12.0.1001.95.
If you have installed SEP SBE 12.0.1001, I would recommend opening a case with support. They can provide you the Cleanwipe tool for the complete removal of all the SEP installs on this system. Once all remnants of SEP are removed then reinstall the SEP 12 client.
Online Portal - https://mysupport.symantec.com/
You can log a case on web portal as well.
QuickStart Guide - Create and Manage Support Cases in SymWISE
http://www.symantec.com/docs/HOWTO31132
How to update a support case and upload diagnostic files with MySupport
http://www.symantec.com/docs/TECH71023