Microsoft has published a list of programs that will not work or that will suffer from reduced functionality after the installation of Vista Service Pack 1.

The list of programs consists mostly of security applications, such as Trend Micro Internet Security 2008. However, programs such as The New York Times Reader application also feature on the list. Users are advised to install updates from the application vendor to fix the problem.

"Windows Vista Service Pack 1 contains many security, reliability, and feature updates for Windows Vista," the company said. "A program may experience a loss of functionality after you install Windows Vista SP1. However, most programs will continue to work as expected after you install Windows Vista SP1."

The list is not considered to be comprehensive, and Microsoft has asked users who encounter problems with other applications to first restart their PC and, if they still encounter problems, to install a newer version of the program or contact the software vendor.

Without SP1 incompatibilities, Windows Vista is already facing an ingrained perception by enterprise users of incompatibility with old systems, said Joseph Sweeney, an analyst at Intelligent Business Research Services.

Issues of back compatibility require regression testing on old applications, making any deployment very painful to do in one install, he said. "In theory, you only have to fix it once, and you should be able to deploy it across your whole environment, but many organizations do not have a highly automated deployment."
The problems with SP1 will only make backward-compatibility issues worse, he said, especially since many companies have been waiting to deploy the operating system until the release of the service stack.

The positive thing about Vista, he said, has been that organizations are stepping back and looking at their deployment methods. Because the desktop market is maturing, the trend would have happened anyway, he said, but Vista's problems have acted as a catalyst.