Microsoft's Windows XP Service Pack Two (SP2) is looking increasingly cursed after the release date appears to have slipped again - if only by a few days.

The software giant had set itself an internal deadline of releasing the new service pack, designed to significantly improve the operating system's security, to manufacturers on 4 August.

But the company said that it decided to hold off because it wanted to make final improvements to the code.

Paul Randle, product marketing manager for the release, said: "The Wednesday schedule was an internal deadline for release to manufacture and we were not happy enough with the product to release it on that day.

"Our internal deadline got communicated by the Australian office and was withdrawn almost immediately."

Randle insisted that this would not cause a delay to the release to customers later this month.

"All I can say [on a final release day] is 'soon'. We are still on track for an August release as before," he explained.

Randle said that the code was undergoing "polishing up" and "tidying rough edges" in part due to customer feedback.

The process of release to manufacture is usually expected to take a minimum of 21 days, allowing time for all OEMs to receive code and set up systems to write it onto new PCs.

SP2 has already been delayed three times. It was first due in June, then July, and now August. Release Candidate 2 of the service pack was officially released on 15 June.

At 80MB SP2 will be one of Microsoft's largest ever service packs, and the first to contain entirely new applications.

The company is relaxing its moratorium on use of cover-mounted CDs for a 90-day period, and CDs will be available in the high street in an effort to get the maximum number of users patched.