Microsoft will craft XP patches after April '14, but not for you
Just because Microsoft doesn't plan on giving Windows XP patches to the public after April 8, 2014, doesn't mean it's going to stop making those patches.
In fact, Microsoft will be creating security updates for Windows XP for months -- years, even -- after it halts their delivery to the general public.
Those patches will come from a program called "Custom Support," an after-retirement contract designed for very large customers who have not, for whatever reason, moved on from an older OS.
