Microsoft is to release Office 2007 SP1 via Automatic Update from 16 June.
The advance warning from the firm is designed to allow users to prepare for the major automatic upgrade.
Users have been able to manually download Office 2007 SP1 from the company's website for the past five months.
SP1 includes Microsoft's new document format Office Open XML, which was last month approved as an open standard by the International Organization for Standardization.
Office Open XML is designed to compete against the open source Open Document Format.