Attacked by Trojan.Backdoor.Generic16.klk and Trojan.Backdoor.Generic2.C? How to Remove Trojan.Backdoor.Generic Variants?

Trojan.Backdoor.Generic16.klk and Trojan.Backdoor.Generic2.C were found by Norton? They seem to be quarantined but come back every time after rebooting? Is there any free and safe removal tools or guides that can remove these Trojan.Backdoor.Generic threats once and for all?  Read the post below for most effective tutorial:

Attacked by Trojan.Backdoor.Generic16.klk and Trojan.Backdoor.Generic2.C? How to Remove Trojan.Backdoor.Generic Variants?