Continuing to maintain Windows XP or unsupported versions of Windows is a significant threat to enterprises, however, particularly in high-risk areas like those mentioned above, where Windows XP will most likely stay entrenched until other investments are made in upgrading infrastructure or equipment. These systems could be secured in many different ways -- such as running them on isolated networks -- but the recent Stuxnet Trojan targeting SCADA systems points out that many times these types of security controls are not effective and the systems are at a high risk.
Running Windows XP on general administrative staff desktops -- which could, nevertheless, be running a variety of other, more secure Windows versions or operating systems -- is not as big of a risk if the systems are otherwise adequately secured by running up-to-date antimalware or other security software that could block attacks, though such adequate security may still be difficult. An enterprise should evaluate the overhead and costs of maintaining older or unsupported versions of Windows (including the potential costs of a breach) as opposed to the effort and costs required to upgrade the Windows version.
There have been a significant number of exploits that victimized Windows XP, which have not had as severe an impact on newer versions of Windows, as newer versions feature many other security improvements that prevent these exploits or minimize the impact of exploits. Current versions of Windows should be seriously considered because of these improvements.
This was first published in July 2010