Microsoft has delayed the release of Windows XP Service Pack 2 (SP2).

The software giant has heavily promoted SP2 as containing key upgrades to the operating system to enhance security.

This includes stronger firewall capabilities, which will be switched on by default, a very basic intrusion detection system that blocks suspicious activity, and a new security centre to simplify the management of settings.

SP2 was due to ship in the first half of 2004, but has now been pushed back until later in the year.

A Microsoft spokeswoman said: "Windows XP SP2 had been scheduled for release in the first half of this year, and now looks as though it will ship sometime this summer.

"The exact time is still dependent on continued customer feedback. Ultimately SP2 will ship when it reaches the quality standards that Microsoft's customers demand."

Andy Buss, an analyst at Canalys, suggested that delaying the service pack to guarantee quality was the right thing to do.

"Most of the fixes Microsoft used to put into service packs are now done with patches. It is better to make sure that the software is right and not 'buggy'."