Back in early December 2005, Microsoft publicly announced that it planned to ship a code-complete version of Windows Vista internally by the end of 2005, setting the stage for a future code-complete Community Technical Preview (CTP) build that the company would issue to testers. However, sources at the software giant now tell me that the company didn't make this milestone, and Microsoft now plans to ship a code-complete Windows Vista version internally by January 31, 2006 instead.

For its part, Microsoft says that Windows Vista is still on schedule. "\[Corporate vice president\] Amitabh \[Srivastava\] said in the November conference call that Microsoft would have the majority of features code complete by the end of 2005 and integrated into the product in early 2006," a Microsoft representative told me. "The development team is right on track with that guidance."

What's odd is that the next CTP--now due on February 17, 2006, according to my sources--will be based on a code branch that predates the code complete version. That suggests that the next CTP might not be code-complete as previously expected, though it will likely to include virtually all of the features Microsoft intends to ship in Windows Vista. Microsoft confirmed today that the next CTP will be issued in February, but didn't corroborate the specific February 17 date.

As I write this, Microsoft is testing Window Vista build 5293 internally. This means that the next CTP build could be in the 5300 range as Microsoft is currently expected to fork the Windows Vista code base for the February CTP on January 23, over four weeks before the planned February 17 ship date.