Microsoft recently published a whitepaper about leveraging the capabilities of Microsoft Virtual PC 2007 to help verify application compatibility.

With each new release of the Windows operating system, Microsoft includes added features and capabilities. The company therefore makes every effort to maintain the highest levels of compatibility possible for existing applications that ran under previous versions of Microsoft Windows. However, before migrating to a newer version of the Windows operating system, customers should confirm that their applications continue to behave as expected.

Microsoft Windows Vista is a highly anticipated operating system. And as such, it is important to perform due diligence before rolling it out. Microsoft claims that most applications that ran with Microsoft Windows XP Service Pack 2 should continue to run with Windows Vista. One concern is the added security found in Windows Vista that builds upon the comprehensive security model introduced with Windows XP SP2.

Security improvements that may affect application compatibility in Windows Vista include:

• Windows Resource Protection (WRP) of system files and protected registry locations. Windows Vista includes protected system file and registry locations for better security and stability. Most applications that previously referenced these locations will automatically be redirected to temporary locations during that session, to ensure application compatibility. However, if your applications' data is attempting to persist data in these protected system areas, you will need to modify those applications, as the temporary locations are removed after each application session.


• Windows Vista User Account Control (UAC). If you are implementing a "Standard User" environment in your organization, applications will need to support standard user permissions as defined in Windows Vista to allow for both Administrative and Standard-User scenarios.


• Running Microsoft Internet Explorer in Protected Mode. To protect the integrity of Windows Vista, Internet Explorer 7 in Windows Vista will now run with Standard User rights, typically not allowing access to all registry or system files. Internet and intranet applications may need to be modified to run in this more restrictive security scenario.


• New firewall/antivirus application programming interfaces (APIs). New system APIs expose the layers of the Windows Vista operating system for antivirus software and firewall manipulation. Applications that perform these functions will need appropriate modifications by using the new system APIs.


• Newly architected Windows Login. Gina is no longer the Windows Login process used in Windows Vista. If you have applications that perform pass-through authentication with Windows, you may need to re-architect these applications.

In addition to the security improvements, there are other Windows Vista innovation features that may affect application compatibility:

• Concerns with 64-bit versions of Windows Vista.


1. 16-bit applications and 32-bit drivers are not supported on 64-bit versions of Windows Vista.


2. Automatic registry and system file redirection is not supported in the 64-bit environment. These changes require that 64-bit applications must adhere to a stronger set of Windows Vista application standards.


• Applications that check operating system version. Applications may check for a specific version of operating system, such as Microsoft Windows 98 Second Edition, Windows 2000, or Windows XP. Although the application may run correctly on Windows Vista, logic in the application may prevent the application from installing if a specific operating system version is not discovered. You can mitigate this issue by running applications in other operating compatibility modes within Windows Vista.


• Microsoft has been testing hundreds of applications and a broad range of partners have tested applications for Windows Vista compatibility and Microsoft has created the Application Compatibility Toolkit (ACT) version 5.0 to help identify application compatibility problems in a corporate environment.

There may be legacy applications in your environment that will not run on Windows Vista, or that you may not be ready to re-engineer or retire. To address these application requirements in your organization, Microsoft has made Microsoft Virtual PC 2007 available as a no-charge solution to meet your needs.

To read the entire whitepaper, download it here.

Posted by David Marshall on August 28, 2006 04:05 PM