Microsoft said on Wednesday that it is beginning automatic distribution of Windows Vista Service Pack 1, the first major update to the year-and-a-half-old operating system.
The company finalized the Vista update in February, but has held off until now pushing it directly to individuals.
Starting Wednesday, the company will start sending it to Vista users who have Windows' automatic update feature turned on. However, the company cautioned that not everyone will get SP1 immediately.
"While Microsoft is beginning automatic distribution today, it's important to note that customers might not see the update download right away since Microsoft is distributing the service pack in phases to ensure a seamless download experience," the company said in a statement.
Vista SP1 was made available for download to customers last month. Service Pack 1 doesn't add much in the way of new features, but rather is a collection of changes designed to fix bugs and improve performance, as well as address competitive concerns raised by Google over Vista's desktop search system. Microsoft also changed how its antipiracy mechanism works with SP1.
The release of Vista SP1 via automatic update is the second milestone this week for the Windows team. On Monday, Microsoft announced it had finished work on Windows XP Service Pack 3. That product will be available for download next week, Microsoft said, but won't start being pushed out via automatic updates until summer.