Windows Vista completed

SEATTLE — Microsoft Corp. finished work Wednesday on its long-delayed Windows Vista operating system, and said the software would be broadly available Jan. 30.

The announcement means Microsoft will meet — just barely — its revised goal of putting Vista in consumers’ hands in the first month of 2007.

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

“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 Nov. 30, and Allchin reiterated Wednesday that corporations who buy Windows licenses in bulk will get the new system this month. That’s also in keeping with the company’s revised release schedule.

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.

The system has been plagued by delays, the most recent of which was blamed in part on efforts to improve security. Microsoft products are a near-constant target of Internet attackers, and the company is often in the uncomfortable position of having to plug holes in its products.