Microsoft Corp. will unveil an add-on to Windows 7 that lets users run applications designed for Windows XP in a virtual machine, the company confirmed Friday.
This is the first time Microsoft has relied on virtualization to provide backward compatibility
Dubbed “Windows XP Mode,” the add-on creates an XP virtual environment running under Virtual PC, Microsoft’s client virtualization technology within Windows 7, said Scott Woodgate, the director of Windows enterprise and virtualization strategy.
In a post to a company blog, Woodgate said the add-on is part of the pitch to convince businesses to migrate to Windows 7.
“All you need to do is to install suitable applications directly in Windows XP Mode. The applications will be published to the Windows 7 desktop, and then you can run them directly from Windows 7.”
Details of Windows XP Mode (XPM) were first reported Friday afternoon by Rafael Rivera and Paul Thurrott, two prominent bloggers who are also collaborating on a book, Windows 7 Secrets, due out this fall.
According to Rivera’s “Within Windows” blog — Thurrott published a nearly identical writeup on his “SuperSite for Windows” — Windows XP Mode will be offered as a free download only to users running Windows 7 Professional, Ultimate and Enterprise, the three top-priced editions of the new operating system.
Windows 7 Enterprise is available only to companies with volume licensing agreements.
Windows XP Mode (XPM) requires processor-based virtualization support and is based on the next breed of Microsoft Virtual PC 7 technology, said Rivera, who also disclosed that Microsoft will include a fully licensed copy of Windows XP Service Pack 3 (SP3) with the add-on.
That, in effect, gives Windows 7 users a way to run older applications without having to pay for another operating system license.
Rivera also touted, as had Woodgate, the ability to run Windows XP applications directly from the Windows 7 desktop without having to first open a separate virtual machine window.
“XPM does not require you to run the virtual environment as a separate Windows desktop,” Rivera said.
“Instead, as you install applications inside the virtual XP environment, they are published to the host (Windows 7) OS as well.
That way, users can run Windows XP-based applications, like IE6, alongside Windows 7 applications under a single desktop.”
Both Rivera and Thurrott trumpeted XPM as a “huge convenience” for Microsoft’s corporate customers.
They predicted that Microsoft would be able to discard older code and technologies from future versions of Windows and instead rely on virtualization to provide backward compatibility.
Thurrott has published a series of screenshots that show XPM’s installation and a Windows XP application running within Windows 7.
Although Rivera and Thurrott said that Microsoft would offer XPM when it ships Windows 7, Woodgate promised that a beta of the new add-on would be released “soon” for Windows 7, presumably on or near the launch of Windows 7 Release Candidate (RC).
Meanwhile Microsoft Corp. confirmed on Friday that it will make Windows 7 Release Candidate (RC) available to the general public on May 5, and make the preview available to MSDN and TechNet subscribers this Thursday, April 30.
The May 5 date had leaked last weekend when a company site briefly published details about the upcoming milestone.
In an entry to a company blog, Microsoft spokesman Brandon LeBlanc also announced that the release candidate would be available before then to subscribers to a pair of services targeting developers and IT professionals.
“The RC is on track for April 30 for download by MSDN and TechNet subscribers. Broader, public availability will begin on May 5,” LeBlanc said.
Earlier in the day, 32- and 64-bit versions of Windows 7 Build 7100, the one that users and bloggers claimed Microsoft would ship as the RC, leaked to file-sharing sites. Both versions were being downloaded in large numbers.
LeBlanc did not provide any details about Windows 7 RC’s May 5 public download, such as the time of day the file will be posted or whether availability would be limited in any manner.
When Microsoft launched Windows 7 Beta in January, it first said that it would restrict the preview to the first 2.5 million users, which caused a stampede that brought the company’s severs to their knees.
Microsoft restarted the launch the next day after sorting out the mess and adding more bandwidth and servers.
Later, Microsoft dropped the download limit and extended the time it would be available to a full month.
Microsoft has told users that they will be unable to do an in-place upgrade from Windows 7’s beta to the release candidate without taking some special steps, however.
Instead, the company has asked users to either revert to Vista before upgrading with Windows 7 RC, or do a clean install because “upgrading from one prerelease build to another is not a scenario we want to focus on because it is not something real-world customers will experience.”
According to another online leak, Windows 7 RC will be offered only in English, German, Japanese, French and Spanish versions.