Microsoft's Windows XP first went on sale in 2001
Microsoft has given yet another reprieve to its seasoned Windows XP operating system.
The cut off date for PC makers to obtain licenses for the software was 31 January 2009.
But now Microsoft has put in place a scheme that will allow the hardware firms to get hold of XP licences until 30 May 2009.
Previously Microsoft extended XP's life until 2010 - provided it was installed on netbooks and low-cost laptops.
Windows XP was originally due to disappear off shop shelves on 30 January 2008. It was to be removed so as to make way for Windows Vista which went on sale to consumers early in 2007.
Despite Microsoft's claims that Vista has sold well, consumers have reacted badly to its release.
Microsoft granted the reprieve largely because of customer's preference for XP.
Many PC makers also got around the restrictions by exploiting a clause in Microsoft's licensing terms that allowed them to offer a "downgrade" licence. Issued with a new PC running Vista it allowed customers to replace it with XP.
The latest reprieve affects PC makers and resellers who were working to a 31 January 2009 deadline to order licences for XP.
Many feared they would have to stockpile licences before the cut-off and hope they could sell them in the coming months.
Now, Microsoft has changed the terms allowing the resellers to order before 31 January but take delivery at any time up to 30 May.
The change in policy is another indication of the general resistance to Windows Vista.
Early versions of Windows 7, the replacement for Vista, are due to appear in late 2009.