Microsoft is reminding users that support for several editions of Windows will end beginning in just six weeks time. It will mean no more security updates, though users can easily upgrade to supported editions without charge.

Support For Early Editions of Windows XP, Vista Ending Soon / Infopackets.com

So if you haven't fully updated your version XP or Vista now is the time to do it.

This is in the paragraph on windows 2000:

In all three cases, Microsoft, naturally, suggests upgrading to Windows 7.

Thats easier said than done and microsoft should know better. Just because you have a xp or especially a 2000 computer does not mean that the computer can handle 7. I think that for general purposes ram is the most important factor. Without enough your computer will seem as slow as molasses (for more info as to why research virtual memory). Everyone I have ever know that doesn't have enough ram complains that their computer is slow know matter what the OS is. Thats because 3rd party programs such as itunes grow and for the most part require more resources. In addition many programs including itunes like to run applications all of the time even when you aren't using the program. Most people don't know this. Now it is true that you should have the most recent service pack but just because that article says so that doesn't mean that you need to (or should) go down to the store and purchase 7. If you have a 2000 machine or old xp machine you probably don't have enough ram. Vista machines probably will have enough but some of the earlier, cheaper vista machines might not have enough resources. On the other hand I've used 7 enough to know that it is more efficient on ram usage than vista but that isn't the case with XP. I think that if you know what you are doing, don't use your computer for much, and have unnecessary programs turned off you could get by with 1 gb of ram with 7 but not Vista. 2 gb though is highly recommended. In addition f you want the fancy aero look or to be able to use media center you will need a fairly powerful graphics card. In summary if you have a computer without enough resources to upgrade to 7 you'll have to get a new computer.