Helping people with computers... one answer at a time.
As official support for Windows XP is phased out, what you can expect from Microsoft will change. Fortunately, it will phase out over a fairly long time.
When Microsoft discontinues support for XP, what will happen if I need to reformat? Will I still be able to get all the updates?
It depend on exactly when you're thinking of. Microsoft won't just stop supporting XP, they'll phase out support. Where in that phase out you happen to be will make a lot of difference.
Fortunately, we have examples of what they've done in the past to make some guesses as to how they'll handle XP.
First, my prediction is that whatever the currently stated dates are for Windows XP's end of life, they'll likely be extended. As we know, many people have been slow to leave XP behind and move to Vista. How Windows 7 will impact this is anyone's guess, but the large remaining installed base of Windows XP, particularly in business, will I believe cause Microsoft to extend support beyond its original plans.
That being said, though, all good things will eventually come to an end.
Based on Microsoft's past phase out of products like Windows 98, I'll throw out this as a likely scenario:
Support for the original product without service packs is withdrawn. Windows XP is actually already at this point since as SP2 is now required. If you attempt to take product updates for an original Windows XP, one of the first things you'll be expected to take is SP2.
Support for early service packs is withdrawn. Once again, Windows XP is already at this point, as SP1 is no longer supported. Your first attempt to update an SP1 machine should result in a download of SP2.
At what Microsoft calls the "supported service pack level" (as I write this, currently SP2 and SP3 for Windows XP), the product is in "Mainstream Support", including security updates, bug fixes and more.
After some period of time (Microsoft documents this as 5 years, but it's been known to change), the product enters "Extended" support phase. Most notably, this means that only security updates are issued. My sense is that the requirements for what is, and is not a security issue also get tougher throughout that phase.
After another 5 years or so, the product enters what Microsoft carefully calls "Self-help online support". Put another way, you're on your own. All the documentation remains online, but actual support and/or updates may no longer be available. Windows 98 and Me are in this phase right now.
Now, interestingly, if you look at the Windows Support Lifecycle information on Windows XP, they currently list the following dates for Windows XP Pro:
General Availability: 12/31/2001
Mainstream Support Retired: 4/14/2009
Extended Support Retired: 4/8/2014
As you can see, mainstream support for Windows XP is scheduled to be retired within weeks of this article being published. Will it happen? Maybe, maybe not. The good news is that security updates will continue to be available into 2014.
Will you be running Windows XP in 2014? To be honest, I hope not. That's kind of like running Windows 98 today - it's just not really a good idea. But if for some reason you must, you'll be able to.