Microsoft has been embarrassed one final time over the delayed release of its heavily hyped and eternally late SP2 update.

The software giant had planned to finish work on the security-focused update for Windows XP at the start of the week and release it on Wednesday. However, the plans were put back again to "ensure that the software meets quality standards".

Unfortunately, nobody told Microsoft Australia, which duly put out a statement on Wednesday saying SP2 had been "released to manufacturing". It was later forced to retract the statement.

A US spokesman had the lowdown - yet another SP2 delay, albeit a short one this time. "There had been a target date to RTM [release to manufacturing] earlier this week, but when the time came Microsoft decided that there was still work that needed to be done for SP2 to meet the quality standards its customers demand," he said.

SP2 will be available through downloads, retail distribution and free CDs, as well as on new PCs. For most users, the download will be between 80MB and 100MB.

To help the large download, Microsoft is updating its Windows Update service to include smart downloading technology that will allow users to interrupt the download and resume it later - especially helpful for users of dial-up Internet connections.

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.

Microsoft has warned that Windows XP SP2 could break existing applications because of the changes that are made. Embarrassingly, one of those applications is Microsoft's own - it has released an update for Microsoft CRM 1.2 because SP2 will prevent the application from running correctly.

A first beta of Windows XP SP2 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, Microsoft has said.