Windows 7 RC Dates Disclosed; 'XP Mode' Unveiled

• By Kurt Mackie
• 04/30/09

Microsoft provided a couple of Windows 7 tidbits Friday, confirming the availability of Windows 7 release candidate (RC) and describing a forthcoming virtualization capability in the new operating system.

On April 30, TechNet and MSDN (Microsoft Developer Network) subscribers will be able to download the RC version of Windows 7, which is currently in beta. The general public will be able to get the Windows 7 RC a little later, on May 5.

Also available on those dates will be Windows Server 2008 R2 RC. Both the Windows Server and the Windows 7 client OSes will be labeled "build 7100." The build number is the same because Microsoft's server and client Windows operating systems share the same code base, a change that started when Windows Vista was developed.

Those testing the beta version of Windows 7, or "Build 7000," will find their Windows 7 OSes expiring on Aug. 1, 2009.

Microsoft also provided sketchy details about an upcoming beta of a virtualization feature for Windows 7. The feature, called "Windows XP Mode," apparently will let users run some older Windows XP-based applications on Windows 7.

"This feature [Windows XP Mode] is aimed at businesses that need to maintain XP compatibility with line-of-business applications," explained a Microsoft blogger. "Essentially, prior to this feature announcement, businesses would have had to have an XP license and use VMware Workstation to unify the desktop with a single start menu. Some would argue that you could also use Virtual PC already but then users would have to actively deal with a second OS. 'Windows XP Mode' abstracts the look of two OSes on a machine so end-users don't have to be bothered about firing up VMs and two start menus."

Windows XP Mode will be available as a free download for users of just three Windows 7 editions: Enterprise, Professional and Ultimate. It works with an application called Virtual PC and comes with "a fully licensed copy of Windows XP with Service Pack 3 (SP3)," another blogger explained.

Other Windows 7 editions won't have the Windows XP Mode option, according to this TechNet forum post.

One Microsoft blogger said that Windows XP Mode is "akin to a standalone, unmanaged version" of MED-V, which is Microsoft's desktop virtualization application available to Software Assurance licensees. Currently, MED-V only supports 32-bit Windows OSes. Possibly, Windows XP Mode might have the same limitation.

"Sixty-four bit isn't mentioned either [in Microsoft's announcement], and I'll be interested to see if it [Windows XP Mode] helps apps which fail on 64 bit anything, forcing some organizations to deploy the 32 bit version of Vista or 7," another Microsoft blogger wrote.

A Microsoft spokesperson, in response to questions about Windows XP Mode, said on Monday that Microsoft does "not have any additional information to share at this time."