The much-anticipated security-focused update to Service Pack 2 for Windows XP will available first in English and German.
Other language versions of Service Pack 2 (SP2) will be released at intervals after the English and German versions are released.
"It will be days in some regions, weeks in others," a Microsoft spokesman said. English and German are also the languages in which Microsoft has offered test versions.
Microsoft expects to finish work on SP2 and release the code to manufacturing next month. The update should be available to the first users some time in August, the spokesman said.
With release to manufacturing, Microsoft will begin the process of distributing the already delayed service pack to users. The delivery will start with the launch of a new version of Windows Update, called Windows Update Version 5.
The latest update service includes smart downloading technology which will allow users to interrupt the large SP2 download and resume it later, which may be especially helpful for users of dial-up internet connections. For most users, the download will be between 80Mbytes and 100Mbytes in size, according to Microsoft.
While Windows Update will be the main delivery vehicle for SP2, Microsoft will also offer users the option of ordering a CD-Rom, and it plans to make CD-Roms available through retailers. Additionally, within 90 days of release all new PCs are expected to ship with SP2 preinstalled.
Although Microsoft has called Windows XP SP2 a service pack, analysts have said that the update really is more comparable to a Windows upgrade. SP2 contains bug fixes and updates, but it also offers new features and makes significant changes to the Windows software in four main areas: network protection, memory protection, e-mail security and browsing security.
A first beta of the Windows XP update was released in December, followed by Release Candidate 1 in March and a second release candidate in June. Hundreds of thousands of developers and IT professionals have already tried out the software. Once released, the service pack will represent one of Microsoft's most broadly tested products to date.
"We have engaged with customers at an unprecedented level to test SP2. In fact, (this is) the biggest technical beta program ever. Over 800,000 people have downloaded and installed SP2," said head of Microsoft Windows client business, senior vice-president Will Poole.
Microsoft has warned that Windows XP SP2 could break existing applications because of the changes that are made. The company has called on all developers and technology professionals to test the service pack to make sure it works with their applications.
Joris Evers writes for IDG News Service