would my windows stay activated in this setup or do i need to buy new?

NavyLCDR said:

Yes.

But as @cereberus posted, nothing happens to the Windows 7 license (product key) when it is upgraded to Windows 10. And the Windows 10 upgrade from a Windows 7 is no longer tied to the Windows 7 license (product key). After an upgrade the Windows 7 product key is stored in the registry, but it isn't used for validating Windows 10 activation. If you clean install Windows 10 on that same computer, there is no longer any trace of the Windows 7 product key.

As @cereberus posted, you can switch between Windows 7 and Windows 10 on the same computer as much as you want to and the activation of one does not affect the activation of the other. However, you only have 1 license for Windows and the EULA only allows for one instance of the software to be installed and activated at a time on the computer.

An example of "dual booting" OEM Windows that 100% complies with the EULA:
1. SSD #1 has the original install of Windows 7 on it. Upgrade that to Windows 10.

2. Remove SSD #1 from the computer. Install SSD #2. Reinstall the original Windows 7 onto it.

3. You can now physically connect either SSD #1 and run Windows 10 or physically connect SSD #2 and run Windows 7. They both will stay activated and won't interfere with other. It would just violate the EULA to have them both connected (installed) at the same time and dual booting. Although if they were connected at the same time and dual booting, Microsoft cannot detect the difference in doing that and just connecting one SSD at a time.

4. Several members of this forum will argue that having them both connected at the same time does not violate the EULA because you are actually "using" only 1 OS at a time on the same computer - but the EULA uses the word "install", not use. There are members here who have dual booted the original Windows 7 and the Windows 10 resulting in an upgrade from the same Windows 7 ever since Windows 10 was first released. Then add dual or triple booting an insider's build of Windows 10 based on the same single license from the original Windows 7, which members here have also done for years.

thank you so much that clears the whole thing up. so basically it seems that what i want to do is is technically agains the EULA, but theres no way for them to detect/know the difference when i am going back and forth between the two SSDs on the same computer

Superfly said:

I think by "install" the EULA is referring to a running version of Windows...

They surely cannot expect one to install and uninstall each version each time it's required.

In a dual boot environment, where only one version can be run at a time - it's not technically an infringement, doing it in a VM, however, will be.

makes sense! thank you!

cereberus said:

I agree with you but this is one for lawyers to debate. It is a principle of law contracts have to be fair, and I think MS would be hard pushed to say it is reasonable to keep installing and uninstalling to meet EULA. I SERIOUSLY doubt MS would ever take a single person to court for this. At most, they might revoke the Windows 7 key, but they would have to alter EULA to make it clear. Of course, they could blanket stop such keys, but then how could you have reverted?

Frankly, I think it is nitpicking when we say it is not permitted, as we all know it works.

I accept (correctly) forum does not condone piracy but reality is there are far more serious EULA transgressions eg you can transfer dgital licences to new device even if original was OEM, or user bought a vlk or own system builder key etc.

So long as we do not encourage use of illegal tools eg password crackers and make it clear when EULA is being violated, I believe as a forum we have met our obligations.

you guys have been really helpful! just finished installing W7 on my second drive and its activated it seems!

cereberus said:

I agree with you but this is one for lawyers to debate. It is a principle of law contracts have to be fair, and I think MS would be hard pushed to say it is reasonable to keep installing and uninstalling to meet EULA.

I think Microsoft's reasonable argument would be that if you want to run two different editions of Windows then buy a license for each one. That seems like a pretty reasonable argument.