Mozilla on Friday announced that next month's Firefox 12 will be the last version to run on early editions of Windows XP and the 12-year-old Windows 2000.

The company also reiterated that it will stop serving security updates for 2010's Firefox 3.6 in April.

Starting with Firefox 13, the browser's minimum requirements will be XP Service Pack 2 (SP2). Firefox 13 will not work on Windows 2000, Windows XP RTM (release to manufacturing, the original mid-2001 build) or XP SP1.

Firefox 12, set to ship April 24 and due to be replaced by the next edition on June 4, will be the last that supports the three older Windows.

"This support change allows us to significantly improve Firefox performance on Windows by using a more modern build system," Mozilla said in a Friday post to a company blog.