While Microsoft officials have mentioned that applications that perform with Vista will need to operate with Windows 7,
Microsoft Office Professional Plus 2010, you will discover exceptions.The 45-page “Windows Application Quality Cookbook” (Version 0.9 of which Microsoft released for download on November 3 on its Microsoft Developer Network site) itemizes some of these potential gotchas in the hopes of getting developers to head off problems sooner rather than later.Though compatibility between Vista/Windows Server 2008 and their successors will be “high,” according to the Softies, it won;t be 100%. From the Cookbook intro:“Though Windows seven and Windows Server 2008 R2 (a k a Windows seven Server) are highly compatible with most of their respective applications written for Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, Windows Server 2008 R2 and their service packs, some compatibility breaks are inevitable due to innovations, security tightening, and increased reliability.”The Cookbook itemizes new features and changes to the Windows 7 operating system (both client and server) that are most likely to affect application compatibility. It ranks these changes from highest to lowest (in terms of severity and frequency) on their potential impact.On Microsoft;s list of Windows 7 changes most likely to affect application compatibility (ordered from highest likelihood of impact on down): Internet Explorer 8—User Agent StringInternet Explorer 8—Data Execution Protection/NXRemoval of Windows MailMicrosoft Message Queuing (MSMQ)—Removal of Windows 2000 Client Support ServiceCompatibility — Operating System VersioningServer Core — WoW64 Is Now an Optional FeatureUser Interface—Enhanced TaskbarMicrosoft Message Queuing (MSMQ)—Improved Queue HandlingWindows Server — Terminal ServicesUser Interface — High DPI AwarenessRemoval of WPDUSB.SYS Driver for Windows Portable DevicesServer — Hyper-VServer — 64-Bit OnlyFile Library Replaces Document FolderNew Binaries—RefactoringCompatibility—Application ManifestMicrosoft Message Queuing (MSMQ)—SHA-2 Is the Default Encryption AlgorithmUser Interface—User Access Control Dialog Updates 1 point worth repeating when thinking about application compatibility and Windows 7: Applications that weren;t compatible with Vista aren;t going to magically operate with 7 (unless the vendors/developers have tweaked them in the past couple of years).As Microsoft officials and some market researchers have cautioned customers, moving straight from XP to Windows 7 will be as painful from an app-compat standpoint as was moving from XP to Vista. That;s why many pundits have suggested business users who aren;t planning on skipping Vista still run some pilots so they can see just how compatible their apps and drivers are likely to be with Windows seven.I still occasionally hear from customers that their apps and drivers don;t work with Vista. Are there any classes of custom programs and/or peripherals with which you;re still having app-compat problems?(Thanks to WinBeta for the original link to the App Compat Cookbook.)