Microsoft began the second beta test of a key virtualization tool this week, with the aim of helping to ease the way for corporate customers who are held back from migrating to Windows 7 by incompatibilities with required older applications.

Version 2 of Microsoft (NASDAQ: MSFT) Enterprise Desktop Virtualization (MED-V) is now available for download for users interested in beta testing the upcoming release.

“MED-V is a bridge to help you create a longer term plan for your more complex applications that may not be compatible with Windows 7 and are too costly to migrate at this exact moment,” Karri Alexion-Tiernan, Microsoft director of product management for desktop virtualization, said on Tuesday in a post to the Windows Blog.

In fact, MED-V is a virtualization component of the Microsoft Desktop Optimization Pack (MDOP), a package of tools meant to help administrators manage and maintain PCs in the enterprise. MDOP is only available as an add-on subscription to Microsoft’s Software Assurance licensing plan.

MDOP provides tools for PC management, application virtualization (App-V), desktop virtualization with MED-V, and asset management, as well as desktop diagnostic tools, the company said. MED-V’s contribution is the ability to manage virtual PC images.

“If you have legacy Windows XP or Internet Explorer 6/7 applications that are slowing down your Windows 7 deployment plans, don’t let them stand in your way,” Dave Trupkin, senior product manager for MED-V, said in a post to the Official MDOP Blog.

Among the new features coming in Version 2 is the ability to deploy MED-V workspaces using existing software distribution tools such as System Center Configuration Manager 2007 Release 2 (R2).

Other new features include streamlined sign-on, automatic application publishing to MED-V workspaces, support for USB drives and SmartCards, and automated guest hibernation at shutdown.

Additionally, Version 2 provides desktop and document redirection so that applications act like they are local when saving, opening or printing, Trupkin added.

The beta of MED-V Version 2 is available for download from Microsoft’s Connect site.