http://www.symantec.com/connect/articles/troubleshooting-liveupdate-issues-symantec-endpoint-protection

http://www.symantec.com/business/support/index?page=content&id=TECH95790&locale=en_US

http://www.symantec.com/business/support/index?page=content&id=TECH98456&locale=en_US

http://www.symantec.com/business/support/index?page=content&id=TECH99909&locale=en_US

http://www.symantec.com/business/support/index?page=content&id=TECH103112

http://www.symantec.com/business/support/index?page=content&id=TECH103176&locale=en_US

http://www.symantec.com/business/support/index?page=content&id=TECH102973&locale=en_US