TechARP has nailed previous service pack schedules for both Windows XP and Vista, said unnamed sources had originally pegged a 22-month development schedule for Windows 7 Service Pack 1. "The earliest Microsoft can realistically release Service Pack 1 for Windows 7 is in the last quarter of 2010," the site said. "There's no required rule for a service pack," observed Michael Cherry. "It's a psychological milestone. They've trained us to wait for SP1." Microsoft would benefit by postponing Windows 7 SP1, Cherry argued. "Windows 7 has pretty good momentum right now, and that might slow down if they announce a service pack. Then, logically, that's when people will wait. It could put the dampers on [Windows 7's] good sales right now." Microsoft declined to comment on TechARP's claims, or on a Windows 7 service pack in general. "Per Microsoft policy, we don’t comment on rumours or speculation," a spokeswoman said. "We have nothing new to announce at this time."