United face a replay tonight against West Ham United.
"We want to try and have a go at this FA Cup," Ferguson told MUTV.
"We haven't had a run for a long time, two or three years, and we have had some bad draws.
"We're at home tonight and we have got to take advantage of that.
"If we get through, we have got another home tie so there's a big incentive for the club to make sure we get through."