Microsoft is gearing up for a return to the federal appellate courts. Next Thursday, the U.S. Court of Appeals for the Fourth Circuit in Richmond will hear the company's appeal of a preliminary injunction ordering Microsoft to carry rival Sun Microsystems' software as part of Windows XP. And on March 13, the U.S. Court of Appeals for the District of Columbia Circuit announced that the never-ending government antitrust case will be heard, once again, by the entire court sitting en banc, rather than by a three-judge panel. The D.C. Circuit appeal was brought by Massachusetts and West Virginia, two states that refused to sign on to the federal government's settlement with Microsoft.