While Microsoft ends support for Windows XP in April this year, Businessweek reports 95% of the world's ATM machines still run on the operating system. In every ATM there's a computer and with the end of support for Windows XP, it means they won't get security updates anymore. Security is obviously an import issue when it comes to ATM machines and ATMs running XP will be no longer be in compliance with security standards.
Unless the machines are running Windows XP embedded, for which support ends by 2016, they get usually updated to Windows 7. This operating system was released in 2009 and while it's already superseded by Windows 8 it seems to be the OS of choice for most banks.
Other banks have made a deal with Microsoft, the company sells tech support agreements which extend the life of Windows XP. These custom deals are very expensive however but buys some time. Upgrading from XP to Windows 7 can cost from a couple of hundred dollar to thousands of dollars, depending how adequate the hardware still is.
Some machines might continue to run on Windows XP after April this year. These will have an increased risk of being infected with malware but it's likely most banks in the modern world won't take the risk.
