Officially, Microsoft casts off Windows XP next week. In all probability it will have to continue patching it whether it whether it likes this prospect or not.

You have to hand it to Windows XP, an operating system that seems immune to age, software fashion, obsolescence and security infirmity. Microsoft’s planners wanted to be done with it long ago but here they are in 2014, stuck in the middle of the slowest software migration in history.

You can take your pick of surveys but I’ll use one from virtualisation firm AppSense that estimates XP’s overall usage rates are down to around 13 percent, with 84 percent of users planning migration to something else within 12 months. Anyone would think that CIOs haven’t had years to plan for all this.

AppRiver’s generous interpretation is that XP doesn’t matter because few use it in anger anyway.

“Part of the reason for lack of concern would appear to be the low level of dependency currently on the XP operating system. While it is still present in many organisations, the numbers would suggest that it is very much on the periphery,” said the firm.

But if XP is under control in organisations, this could turn out to be beside the point because more than enough of their customers plan to stick with XP. Exactly how many nobody really knows because they've been shunned like lepers since Vista appeared in 2007. It is among these people that the real effects of XP’s half-life will be felt rather than among businesses able to buy support contracts and run virtualised appliances.

Microsoft claims that hold-outs will suffer the indignity of mounting security exploits for unpatched flaws but will it really be that simple? More likely, the week the first serious unpatched flaw appears in the OS or IE8, Microsoft will be forced through a mixture of moral hazard and sheer embarrassment to offer a fix to stem criticism about abandoning customers to their fate.The alternative will be to watch a serious vulnerability in the OS being used to pwn frightening numbers of victims with impunity.

On top of this you have the vast numbers of Windows XP systems used in China,virtually none of which HAVE NEVER BEEN PATCHED in their entire existence thanks to their pirated status. Microsoft isn’t going to get away from XP quickly or cleanly any more than the industry will. Privately, it knows this.

Doubtless, tens of millions of people will continue using an insecure Windows XP after 8 April, possibly long into the future. This is entirely the fault of the last Microsoft regime.By driving up the underlying hardware requirements needed to run Vista and Windows 7 between 2007 and 2009, Microsoft cut off any upgrade path for XP users running Pentium 4 processors and 1GB of RAM. Late in the day, we now know that many users decided they were happy with what they had.

It’s fashionable to blame the users for not upgrading but I prefer to see it as an indictment of Microsoft’s business model of planting operating systems in the ground like trees and then ambushing people with software axes an arbitrary number of years later.  Microsoft compounded the issue by selling XP to run netbooks that had, ironically, been invented to get away from the top-heavy Wintel idea of what personal computers should be. Scandalously, that opportunistic policy ran as late as 2010. It's incredible that Microsoft happily sold licenses for XP so late in the day simply because netbooks couln't run the preferred version.

The next date for Microsoft to worry about is 14 January 2020, the day Windows 7 has its XP moment.  Who would honestly bet against that going out kicking and screaming too?