Improving Electronic Voting Standards and Disclosure Act of 2004 - Amends the Help America Vote Act of 2002 to: (1) establish specific requirements for software used in electronic voting machines in Federal elections; (2) prohibit Election Assistance Commission accreditation of a laboratory unless it meets standards the Commission may establish to prevent the existence or appearance of any conflict of interest in the testing of voting system hardware and software; and (3) require the posting of notice of the availability of administrative complaint procedures for individuals who believe that a voting machine or other equipment used in the election is not working properly, or who otherwise believe that a State or jurisdiction is not in compliance with the requirements of this Act.