Software giant Microsoft offered IT support services an early Christmas present with the first non-beta version of its Windows XP Service Pack 3 (SP3) upgrade.

The package of performance enhancing changes and security updates should theoretically reduce the number of problems referred to IT helpdesks, although tech departments still have to install it on all systems first.

SP3 marks the final update for Microsoft's XP operating system as the Redmond-based firm turns its attentions to Vista.

A Microsoft spokesperson warned that this release of the SP3 update is not yet the final version.

"This pre-release software is provided for testing purposes only," the spokesperson said.

"As this is a release candidate, we strongly encourage only those who are comfortable installing pre-release code to download Windows XP SP3."

And the software company was keen to talk up the benefits of the newer operating system, saying in a recent white paper: "Vista provides the most advanced security and management capabilities of any Windows operating system".

A final version of XP SP3 is expected to be released in the New Year.