Did the FBI know before 9/11 the identities of the alleged hijackers?

Did Rumsfeld know before 9/11 that the attacks would take place? 

  In mid-June, F.B.I. director Robert Mueller III and several senior agents in the bureau received a group of about 20 visitors in a briefing room of the J. Edgar Hoover Building in Washington, D.C. The director himself narrated a PowerPoint presentation that summarized the numbers of agents and leads and evidence he and his people had collected in the 18-month course of their ongoing investigation of Penttbom, the clever neologism the bureau had invented to reduce the sites of devastation on 9/11 to one word: Pent for Pentagon, Pen for Pennsylvania, tt for the Twin Towers and bom for the four planes that the government had been forewarned could be used as weapons