Microsoft Wednesday finally completed work on its Vista client operating system and plans to release the code to corporate users this month.

The “release to manufacturing” was announced this afternoon by Jim Allchin, co-president of the platforms and services division at Microsoft. Allchin, who has been with Microsoft for 16 years, is retiring after Vista officially ships.

“This is a good day,” said Allchin, when introduced to kick-off a press conference held at 11 am PST. “We signed off on Vista less than an hour ago. Vista is rock solid and ready to ship.”

Microsoft says the next steps are to release the software officially at a launch party in New York on Nov. 30, and for PC/device manufacturers and independent software vendors to finalize work on their Vista supported products. The Nov. 30 event also will include the launch of Office 2007 and Exchange Server 2007.

Vista will be available on or before Nov. 30 to volume-licensing customers, Allchin said. The consumer versions will be available on Jan. 30, Allchin announced. Microsoft’s partners are issuing upgrade coupons for users who buy PCs during the holiday season that are loaded with Windows XP.

Vista has been in development for more than five years and has endured a number of delays, set backs and feature cuts.

But Allchin gushed over Vista, thanking all the testers who hammered on the operating system and all those that provided feedback. He said hardware and application compatibility with Vista is an all-time high for any release of a Microsoft operating system.

“I can’t stress how proud I am of this release,” he said. “My hope is that this OS will be remembered for the huge progress we have made in terms of quality and security, in particular.”

Allchin went on to detail performance, reliability and security features that he said makes Vista stand out. In terms of performance, Allchin mentioned Super Fetch, Ready Boost and Ready Drive. In terms of reliability, he said Vista has gone through 16 technology previews since Beta 1 shipped in August 2005. He also said more than 60,000 PCs inside Microsoft are already running Vista.

Security enhancements include User Account Control, which restricts administrative rights on the desktop. Vista’s Enterprise version also includes exclusive features such as BitLocker Drive Encryption, virtualization technology and Unix integration. The Enterprise version is only available to customers with Software Assurance maintenance contracts.