Windows Vista Enterprise edition is available as a free download from Microsoft as of the end of the past week. Microsoft has explained the initiative as a way to offer users the chance to test-drive its latest operating system. However, this is also a great opportunity for users to get their hands on the Enterprise edition of Vista.

While Windows Vista Home Basic, Home Premium, Business and Ultimate can be bought by end users with no problems, there are editions of the operating system with limited availability. It is the case of the European versions and of the Starter edition of Vista (delivered exclusively pre-loaded on machines to developing markets). Vista Enterprise is also available only to Microsoft's Software Assurance customers via volume licensing.

Still, with the pre-configured VHD offered by Microsoft, Windows Vista Enterprise can be road-tested for a total of 30 days. Users have to know that the "slmgr" method for prolonging the initial grace period of Vista up to 120 days does not work on the Enterprise edition as the platform features a different activation mechanism.

But if you are thinking about giving Vista Enterprise a run, on your Windows XP, then you should know what not to do with the VHD. This is also valid for the additional VHDs containing free software offering from the Redmond Company. The Compressed Folders feature of Windows XP can produce corrupted files when applied to the VHD downloads.

If you have downloaded a few VHDs on the same location and want to compress them to save space, it is better to avoid XP's Compressed Folders feature. "When you create a compressed folder (ZIP file) that is larger than 4 gigabytes (GBs), the file may no longer be readable, and may become corrupted. You do not receive any error message when you create the file, but you cannot read the file after you create it," reveals Microsoft in KB 301325.

This issue is related to the lack of support for files larger than 4 GB. Just compress all the VHDs individually or make sure that you stay under 4GB.