Many users are taking up the offer for Windows 7 "Upgrade," which requires the user to have a pre-existing, legitimate copy of Windows 2000, XP, or Vista already pre-installed on the user's machine.

However, Microsoft has recently confirmed it is technically possible to install an upgrade-only edition of Windows 7 on a machine that doesn't already have another version of Windows pre-installed. That said, the firm has also pointed out that doing so is an illegal breach of licensing conditions.

Several websites have printed what they describe as 'workarounds', which use an upgrade disc to install the new operating system on an empty machine. The process appears to take advantage in the way the installation works and doesn't involve unauthorized copying of the Windows DVD media.

The financial savings from using this method depends on which edition of Windows 7 the user purchases, but it can be around the $100 mark.

Clean Install Trick "Breaches License"

In a post on a company blog, Microsoft's Eric Ligman writes that using the Clean Install 'upgrade' trick on a machine that doesn't have a pre-existing copy of Windows, breaches licensing restrictions. He explains that using Windows 7 requires either a full license (such as that included with copies on new machines) or a combination of an upgrade license and a license for a previous version. In the latter case, the previous version must be the official release and not a test or beta edition.

Ligman condemned sites that provided the "workaround" without explaining the licensing rules. He said such sites "give the impression that because [the workaround] is technically possible, it is legal to do. Unfortunately, by doing this, they irresponsibly put end users at risk of loading unlicensed software." (Source: msdn.com)

Can Upgrade Trick be Detected?

It's interesting that Microsoft has posted a full-page response to this issue, knowing that doing so will inevitably draw more attention to the Win7 upgrade trick loophole. This begs the question: is Microsoft's response simply for "damage control" or does this warning imply that a breached license will cause a PC to fail the Windows Genuine Advantage (WGA) check? In the latter case, users would have limited access to Windows Updates, meaning that their PC could be more vulnerable to malware and hacker attacks.