A large number of firms could be at risk when Microsoft stops offering support for the ageing Windows XP next April. That is the implication of a recent British survey that found 58% of IT departments had not begun the process of migrating from the decade-old OS.

Microsoft will stop releasing security updates on April 8, 2014. Firms that use Windows XP beyond that date could be attacked via unpatched security vulnerabilities in XP. Despite this, the survey of 250 British CIOs and CTOs also found that one in ten IT chiefs intended to continue using the operating system after the April deadline.

The survey was conducted by Camwood, a British software consultancy.

"If you haven’t yet started the process and unless you complete your migration within the next year, your business-critical data will be left open to corruption, infection, theft or exploitation," said Camwood in a statement.

Windows XP, which came out in 2001, is still the second most popular version of Windows, after Windows 7 - 38.7% of PCs use XP, according to NetMarketShare.

“In these tough economic times, it is not surprising that business leaders do not want to invest a substantial amount of money in something that essentially isn’t broken, as is the case with Windows XP today,” said Adrian Foxall, CEO of Camwood. “The message that Microsoft is switching off the lights is being received loud and clear by the IT community, but it would appear that the business don’t understand the perils of remaining on XP."