May 16, 2011 12:46 GMT  ·  By

Microsoft is offering a collection of free Windows copies for download, comprising the past three releases of the operating system. A set comprising Windows7, Windows Vista and Windows XP can be grabbed free of charge via the Microsoft Download Center.

The software giant has introduced a major overhaul to the Internet Explorer Application Compatibility VPC Images it has been offering web developers since after the release of IE7.

The new Windows Virtual PC VHDs have been updated and expanded, in order to help web devs to test drive their sites in different IE versions running on Windows 7, Vista and XP.

As was the case with past IE App Compatibility VPC images, the latest releases contain different copies of Windows and of IE packed as virtual hard disk images, designed to run inside Microsoft’s virtualization solutions.

“The password to login to all of these images is Password1 and the username will be present when you first login,” the company said.

Here is a list of what the new IE VPC downloads actually bring to the table:

Windows XP Image - Contains: Windows XP SP3 with IE6 VHD file and was fully patched on April 14, 2011. This image also contains the install files for IE7 and IE8. If you want to have separate base XP images for IE7 and IE8, you can copy the VHD, rename it, and install the other desired version of IE. Expires: This image will shutdown and become completely unusable on August 09, 2011.

Windows Vista Image - Contains: Windows Vista SP2 with IE7 VHD file and was patched through March 2011. The install files for IE8 and IE9 are also available for install on the image.

Windows 7 IE8 Image - Contains: Windows 7 SP1 with IE8 VHD file and was patched through March 2011. The install files for IE9 are also available for install on the image.

Windows 7 IE9 + Tools Image - Contains: Windows 7 SP1 with IE9 VHD file and was patched through March 2011. This image also has the ACT Toolkit 5.6, IECTT, and Expression Super Preview software installed.”

Microsoft notes that customers should be expected to be asked to activate the virtualized copies of Windows, since the product keys for all platforms were deactivated. The software giant stresses however that even activated, not one of the three images will pass genuine validation.

“Immediately after you start the Windows 7 or Windows Vista images they will request to be activated. You can cancel the request and it will login to the desktop. You can activate up to two “rearms” (type slmgr –rearm at the command prompt) which will extend the trial for another 30 days each time OR simply shutdown the VPC image and discard the changes you’ve made from undo disks to reset the image back to its initial state,” Microsoft said.

“By doing either of these methods, you can technically have a base image which never expires although you will never be able to permanently save any changes on these images for longer than 90 days.”

The Internet Explorer Application Compatibility VPC Image are available for download here.