Trojan.Poweliks - Need help!

Greetings,

I desperately need help removing Trojan.Poweliks.....based on my Norton security history, Risk Name - System Infected - Trojan.Powelik.Activity.  I first tried a system restore but eventually received a message that said "Unable to run system restore."  I then tried downloading a few removal tools but kept getting yet another message that said "Your current security settings to not allow this file to be downloaded."  I'm completely at a loss so any help would be greatly appreciated.

Thank you!!!