SEATTLE, Washington (AP) — Microsoft Corp. said Wednesday it has completed work on its long-delayed Windows Vista operating system and plans to release it to consumers January 30.

The announcement means Microsoft is on track to meet its revised release schedule.

Jim Allchin, co-president of the Microsoft division that includes Windows, said in a conference call that Windows Vista’s code was released to begin manufacturing copies early Wednesday.

“This is a good day,” Allchin said.

Microsoft had previously said it would release Vista to big business clients at an event at the Nasdaq Stock Market on November 30, and make it available to consumers sometime in January.

The release will be the first major upgrade in more than five years to the operating system that powers most of the world’s personal computers. Vista boasts improved graphics, more effective tools for finding documents, pictures and other items on personal computers, and a new Internet browser, among other changes.