Virus found but "Removed Failed" for Backdoor.Trojan

On my backup drive scan, I received a Threat Detected alert for Backdoor.Trojan, but Norton Internet Security V 20.2.1.22 says Remove Failed.  The file is located in a Windows backup file:

 

Full Path: h:\homehpdec2011\backup set 2012-11-26 170242\backup files 2013-01-27 160001\backup files 10.zip
Threat: Backdoor.Trojan

 

[fedex-tracking_information-08_2012.exe] inside of [fedex-tracking_notification-08_2012405835727030.zip] inside of [unknown00cfbfd8.data] inside of [inbox] inside of [h:\homehpdec2011\backup set 2012-11-26 170242\backup files 2013-01-27 160001\backup files 10.zip] - Infected

 

How do I remove it?

 

Thanks,

Mike