Microsoft has released Windows Vista Service Pack 1 and Windows Server 2008 to manufacturing.
The company said the new client and server operating systems would help improve the software's efficiency, performance and security.
Windows Vista Service Pack 1 (SP1) will be available to customers from March, starting with Microsoft Volume Licensing customers.
Windows Server 2008 will be available for purchase to new customers from 1 March.
Microsoft Volume Licensing customers with active Microsoft Software Assurance coverage or an enterprise agreement will be able to download the server software towards the end of February.
The new Microsoft SQL Server 2008 and Visual Studio 2008 will be available at the same time.