Microsoft ranks Windows 7 features most likely to affect app-compatibility
While Microsoft officials have said that applications that work with Vista should work with Windows 7, there are 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.
Even 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:
"While Windows 7 and Windows Server 2008 R2 (a k a Windows 7 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 String
- Internet Explorer 8—Data Execution Protection/NX
- Removal of Windows Mail
- Microsoft Message Queuing (MSMQ)—Removal of Windows 2000 Client Support Service
- Compatibility — Operating System Versioning
- Server Core — WoW64 Is Now an Optional Feature
- User Interface—Enhanced Taskbar
- Microsoft Message Queuing (MSMQ)—Improved Queue Handling
- Windows Server — Terminal Services
- User Interface — High DPI Awareness
- Removal of WPDUSB.SYS Driver for Windows Portable Devices
- Server — Hyper-V
- Server — 64-Bit Only
- File Library Replaces Document Folder
- New Binaries—Refactoring
- Compatibility—Application Manifest
- Microsoft Message Queuing (MSMQ)—SHA-2 Is the Default Encryption Algorithm
- User Interface—User Access Control Dialog Updates
One point worth repeating when thinking about application compatibility and Windows 7: Applications that weren't compatible with Vista aren't going to magically work 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 7.
I still occasionally hear from customers that their apps and drivers don't work with Vista. Are there any classes of custom applications and/or peripherals with which you're still having app-compat problems?
(Thanks to WinBeta for the original link to the App Compat Cookbook.)