As we announced in 2008, support for Windows XP Service Pack 2 (SP2) will end on July 13, 2010. Support for Windows 2000 will end on the same date. Support for Windows Vista Release to Manufacturing (RTM) will end on April 13, 2010.
NOTE: There is no Service Pack 3 for the 64-bit version of Windows XP. If you are running the 64-bit version of Windows XP with Service Pack 2, you are on the latest service pack and will continue to be eligible for support and receive updates until April 8, 2014.
To find out if you are running the 64-bit version of Windows XP, right-click My Computer, then click Properties. If you do not see "64-bit" listed, then you are running the 32-bit version and you need to install Service Pack 3 . If "64-bit" is listed under System, then you are running the 64-bit version.
If you are running Windows Vista RTM then you need to download and install at least Service Pack 1 but I would recommend installing Service Pack 2. If you already have either of those installed you will continues to be eligible for support.
If you are running Windows 2000 you will need to upgrade to XP SP3, Vista SP1 (or SP2) or Windows 7 to continue to receive support.
You can find out more about what is supported and until when on the enterprise products support lifecycle page.