This is not intended to insult anyone.....just an observation from reading posts concerning Windows licensing.
There are some people here, computer repair professionals, who are misguided when it comes to proper Windows licensing and post inaccurate information as fact without any references to back up their claims.
Using a Windows disc that was not intended for the target system may result in being able to install & activate Windows, but it may not be legal to do so. Different Windows versions have different End User License Agreements and as computer professionals we are bound to adhere to them. It is not the end user that is agreeing to them, it is the installer....you.
All the information concerning proper Windows licensing is on Microsoft's website. I'm not referring to the forums, I'm referring to KB articles and the OEM Partner Center. I've posted links a few times....even in this thread.
In an effort to distribute accurate information, I submit the following links:
Microsoft OEM partner Center FAQs
How to replace Microsoft software or hardware, order service packs, and replace product manuals
Microsoft Software License Terms (Windows 7)