Microsoft has started shipping the first versions of Windows XP Service Pack 3 to PC manufacturers.

Current XP users can expect to see the service pack become available for download on 29 April.

Windows XP SP3 contains minor performance and stability enhancements, in addition to a cumulative security update. It is the first service pack to be released for Windows XP since SP2 in 2004.

The pack will also contain updates which will make it easier for network administrators to manage SP3 machines alongside Windows Vista PCs.

SP3 is expected to be the last major update for Windows XP. Microsoft will stop offering the operating system to manufacturers on 30 June, but will still allow vendors to sell the operating system on " ultra-low cost" PCs.

Windows XP SP3 will be available through Microsoft's Windows Update tool or the Microsoft Download Center website. Automatic distribution of the patch will begin later this summer through Automatic Update.