April 02, 2013, 6:44 AM — The decline in usage share of Windows XP, which is slated for retirement in 53 weeks, has slowed significantly, hinting that millions of its users will hold onto the operating system much longer than some, including Microsoft, expect.
Data published monthly by California-based Web analytics company Net Applications indicates that XP's long-running slide has virtually stalled since Jan. 1.
In the past three months, Windows XP's monthly drop in share has averaged just 0.12 of a percentage point. That's less than a fifth as much as the 12-month average of 0.68 percentage points.
Other averages point to a major deceleration in declining usage share: XP's most recent six-month average decrease of 0.42 percentage points was less than half the 0.94 point average for the prior six months.
Likewise for longer timespans. In the last 12 months, Windows XP has dropped an average of 0.68 percentage points, while in the 12 months prior it fell by 0.83 percentage points.
In other words, in the second half of a 12-month stretch, XP's decline slowed by 55%; in the second year of a two-year span, it slowed 18%.
The slowdown paints a picture that must depress Microsoft, which has been banging the upgrade drum at Windows XP users for nearly two years, and has repeatedly warned them that free security updates will stop after April 8, 2014.
Net Applications' data can also be used to roughly plot XP's future usage share.
If the average decline of the last 12 months holds, XP will still account for 30% of all personal computers at the end of April 2014, or 33% of all systems expected to be running Windows at that time.
Recent estimates of XP's future by analysts, however, have been more conservative, with experts from Gartner and Forrester Research predicting that 10% to 20% of enterprise systems will still be on the aged OS when support stops.
Microsoft has not pegged XP's current corporate share, but the Redmond, Wash., software developer clearly knows it's large: In January, during the company's last quarterly earnings call, CFO Peter Klein said 60% of all enterprise PCs were running Windows 7.
Since few businesses adopted Windows Vista -- and with Vista's usage share now under 5%, some that did likely ditched it -- the remaining 40% must, by default, largely be Windows XP.