<p>WASHINGTON (Reuters) - The FBI (news - web sites) said on Thursday it may have to scrap a new $170 million computer program designed to allow agents to share information instantly and fix a main problem identified after the Sept. 11 attacks. The software is already outdated and inadequate, with the bureau able to use only about one-tenth of the program, an FBI official said on condition of anonymity. Failure of the Virtual Case File software is the latest glitch in the bureau's effort to overhaul its computer system, one of FBI Director Robert Mueller's priorities in the agency's reorganization after the Sept. 11, 2001, attacks. "I am frustrated," Mueller said when asked about the software at a news conference in Birmingham, Alabama. "There were problems we did not anticipate." Investigations showed the FBI and other intelligence agencies failed to share information that could have helped stop the hijackers from crashing four airplanes into the World Trade Center, the Pentagon (news - web sites) and a Pennsylvania field. The FBI was criticized for its old system of keeping paper files that could not be accessed by agents in the field. The FBI official said part of the problem was that the FBI was trying to completely revamp a very antiquated system all at once. He said in the future, changes should be done in stages, so software will not be outdated by the time it is launched. "I compare the FBI to changing wheels on a car that is going at 70 miles per hour," the official said at a briefing. Though Mueller said the bureau was trying to salvage the software, the FBI official said there was a "good possibility" the FBI would need a completely new system, which would mean most of the $170 million was worthless.</p>