Michael A. Silver, a research vice president at the analyst firm, said that companies, particularly those that have standardised on Windows 2000, should waste no time in beginning Vista evaluations.
"Beta 2 is always a major milestone for new Microsoft products. Stable, compatible and successful beta 2 releases are integral to Microsoft's ability to hit its target dates and ship Windows and Office on time," said Silver.
"For many businesses, beta 2 of Vista and Office 2007 will mean that serious testing has commenced. The amount of testing you should plan for will depend on how quickly you intend to adopt Vista and Office 2007 when the final versions become available."
Silver added that, while he believes Microsoft will meet its target date for shipping Office, he is skeptical that it will meet its launch date for Vista.
For the first time with these forthcoming software releases, Microsoft will address the issue of testing the new products without installing them.
Silver pointed out that version 5 of the Application Compatibility Toolkit, a beta of which is now available, will include agents that can be run on Windows 2000 and XP PCs, and will look for behaviour "not allowed" in Windows Vista.
The analyst warned all Microsoft users that application compatibility is not assured at beta 2 or even at the release candidates that will follow.
"Applications that don't work today may work when the products are finally released, and vice versa. More testing will be required when the products are released," he said.
"Knowing which applications don't work in beta 2 will allow you to speak with your internal developers, independent software vendors and Microsoft to ensure that the problems are resolved in the final release.
"Even if an application works, if your vendor refuses to support it on Windows Vista, you may still decide that there is too much risk to proceed until support is guaranteed.
"Be sure to talk to the vendors of your critical applications to understand their timeline for Windows Vista support."
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