Microsoft SMB Community Blog : Regardless of what any hack says, a Windows 7 Upgrade is an Upgrade. What you need to know.
[...] Here are some very basic facts:
- When you purchase software, you are purchasing the rights to run the software according to the terms of the End User License Agreement (EULA) that comes with that software.
- When you install that software, you are agreeing to the terms included in the EULA you purchased.
- For instance, in the Windows 7 EULA it states, “By using the software, you accept these terms. If you do not accept them, do not use the software. Instead, return it to the retailer for a refund or credit.”- When you purchase an Upgrade license, the included EULA states that you must already own a qualifying full license to upgrade from in order to use the Upgrade license, hence the term “Upgrade.”
- For instance, in the Windows 7 EULA it states, “To use upgrade software, you must first be licensed for the software that is eligible for the upgrade.”To put it simply, here is a graphical representation of what this means:
General Example Example with Product Names 
In stark contrast to:
General Example Example with Product Names 
So when these posts and write-ups state that you can install clean from an Upgrade piece of software and they fail to mention that you need to own a qualifying software license to be legal to use the Upgrade software for the installation, they give the impression that because it is technically possible, it is legal to do. Unfortunately, by doing this, they irresponsibly put end users at risk of loading unlicensed software. Because of this, I am putting this post up to try and clarify the truth behind what an upgrade license is and provides so that hopefully people will not find themselves misled by some of these other posts and articles that may mislead them to believe something that is very wrong due to their lack of inclusion of this important piece of information. If the posts or write-ups you saw did include this information, then kudos to that writer for providing the accurate information.
This is why DRM or whatever equivalent evolves will be around in the future - trust in people is really difficult sometimes.
