Please note that SEP 12 is a different product than SEP 11.
Symantec Endpoint Protection Small Business Edition does not support migration from Symantec Endpoint Protection 11’s Symantec Endpoint Protection Manager (SEPM) to Symantec Endpoint Protection Small Business Edition’s Symantec Protection Center (SPC). SEPM will have to be uninstalled prior to installing Symantec Endpoint Protection Small Business Edition’s Symantec Protection Center. If desired the Symantec Endpoint Protection 11 policies can be exported and imported into the Symantec Endpoint Protection Small Business Edition’s Symantec Protection Center after installation.
http://www.symantec.com/business/support/index?page=content&id=TECH94178&locale=en_US
Best,
Thomas