Application Compatibility: Operating System Versioning
The internal version number for Windows Vista® and Windows Server® 2008 is 6. The GetVersion function will now return this version number to applications when queried.
Version 6 is the next major version number after Windows XP® (version 5.x).
The manifestation of this version change is very application-specific, as follows:
Any application that specifically checks for the OS version will get a higher version number.
Application installers might prevent themselves from installing the application, and applications might prevent themselves from starting.
Applications might warn users and continue to function properly.
Some applications might become unstable or crash.
Most applications will function properly on Windows Vista and Windows Server 2008 because the application compatibility in Windows Vista and Windows Server 2008 is very high. However, for applications and installers that check for OS version, a Compatibility mode is provided in Windows Vista and Windows Server 2008.
Users can right-click the shortcut or the executable file and apply the Windows XP SP2 compatibility mode from the Compatibility tab. In most cases, this mode should enable the application to work as it did on Windows XP without the need for any changes to the application.
Generally, applications should not perform OS version checks or, at minimum, always accept version 6 or later for the OS. This behavior should be followed unless there is a very specific legal, business, or system-component need to do this version check.
Ensure that any drivers that an application uses are user-mode drivers as much as possible to maintain multiplatform (32-bit and 64-bit) compatibility.