win10

So where to download it? I find only strange links on windows site?

I do not have a win7. Is there no download?

All my win7 did was declare itself pirated because i switched the motherboard.

Sigh.

This link worked, thank you.
Okay, other question how does M$ know I installed it on other devices?

Yes, hardware identification. Your cpu has an ID (special instruction delivered curtosy of Intel), your disk has an ID, your ethernet and wireless cards have ID(s): MAC addresses. Combine any of them to determine the identity of a computer.

Copy from microsofts website:

quote: The tools collect information such as: Computer make and model Standard computer information, such as your IP address, operating system version, software version, browser version, and regional and language settings A unique number assigned to your computer by the tools (Globally Unique Identifier or GUID) Product Key (hashed) and Product ID BIOS name, revision number, and revision date Hard drive volume serial number (hashed) Whether the installation was successful if one was performed The result of the validation check, including error codes and information about any activation exploits and any related malicious or unauthorized software found or disabled, including: The activation exploit’s identifier The activation exploit's current state, such as cleaned or quarantined Original equipment manufacturer identification The activation exploit’s file name and hash of the file, as well as a hash of related software components that may indicate the presence of an activation exploit The name and a hash of the contents of the computer's start-up instructions file (commonly called the boot file) to help us discover activation exploits that modify this file.

And by all means, read this: http://www.makeuseof.com/tag/how-to-make-your-windows-7-pc-genuine-again-after-a-hardware-upgrade/

The upshot of which is that if you made (several) hardware changes that made your copy of windows non genuine, then you need to reactivate your windows copy using an old fashioned phone call to a service centre, the quality of which varies.

Note that they can easily check whether you are still using your windows copy only on the changed hardware because each time windows update does its thing it will check your validation status. Several different hardware configurations with the same activitation key doing windows update in short intervals of time (say, a month) gets the activation key blacklisted so you can call but you will not get your copy validated again.

Are you sure that works? Can you point to examples of people that sucessfully managed to do that?
(I would expect it to only work if you use the same model of motherboard, for warranty reasons...)

The issue with the "guidelines" shown above is that they are (intentionnaly?) vague, which means you're at the good mercy of Microsoft('s algorithms?) which decide whether you have a "genuine" licence or not...

There is no "call microsoft" button. I guess i have to call them in a non-automated way?

i did not have OEM (old student MSDNAA licence) and used multiple mainboards (or you can say i installed it on 3 diffrent PC/Laptops in random order multiple times)

It is possible to use pirate software to make your copy forced-genuine after-the-fact.

Google or piratebay "windows loader".