Windows 10: How to get product key of old OS (Win 7) after upgrading to Win 10?

I am tired always to fight these "I know better" posts without any whatsoever factual information, I am downloading a Windows 8.1 Update 1 image at the moment, I will make a video showing that I can use the same key as many times as I want to for activating it but as soon as I have upgraded it to Windows 10 with this underlying key, the key is no longer valid.

Download of 8.1 Update 1 ISO image started just now, installing it a couple of times then upgrading to 10, plus making the video takes a few hours but I will post it here when ready.

 

Ok thanks, I just got back an external USB drive then*Smile(I was just goin to keep it a year any how, just to have*Wink)

 

You can do that Cliff but as Kari says there is no point.

I did use slmgr /upk <xxxx.xxxx.etc> to remove one license from broken laptop before I moved it to a VM.

I try to be honest (that is the only reason I did it). I turned on the old 8.1 laptop and it said "not activated" but I only used it to get some files I forgot.

It is up to you how honest you want to be.

On this site it seems mentioning using an invalid MS license is interdit but mentioning torrenting movies/films is fine - even if it is with a "nudge-nudge, wink-wink" as some VIP's do.

Personally I disagree - I think if you want it you should pay for it - but it isn't my business either way.

 

Kari, NavyLCDR, I had exactly the same question. I have not tried out, but I also was not sure, whether it would be possible to use the underlying Windows version after a PC had been upgraded to Windows 10.

So you, Kari, have tried and your result is that it is not working. This confirms what I had feared (and what I was told would be wrong).

However, there is one question, which is still open:

When you upgrade to Windows 10, Microsoft gives you this 30 day period in which you can roll back to the previous OS. When you, Kari, say that the old licence can no longer be used, does that then also mean that you cannot really go back to the old OS, as Microsoft would then no longer activate it as well? I think people are using this rollback feature and (apart from a few bugs) it is generally possible to go back.
How does that fit to your observation that the old OS can no longer be activated?

(And now don't tell me that activation status would somehow be preserved so that no new activation is needed. This does not help; one might still want to change some hardware so that a new activation becomes necessary. Then this is the point, at which you would be screwed, if the activation server would no longer activate your licence.)

 

30 days is only because cleanmgr.exe deletes windows.old etc. I have restored back many many times since July.

 

And have you, halasz, actually done a new activation of that old OS? If the old activation status was just retained (I believe it is, after all the rollback basically just gives you back your old system), then you don't really know, if it would activate again, as there has been no need to talk to an activation server. It would just still be activated, not again. That is a difference!

Basically I understand what Kari is saying, that the old OS was no longer activatable, but I don't understand how that fits to that other people could still use the previous OS without problems.

 

Yes, I can tell you why. Many members here run dual boot with Windows 10 on one partition and their old operating system on another partition. Violates the EULA, sure, but the old product key is in no way invalidated.

Second. I have restored a laptop that had Windows 8.1 factory installed with the product key stored in bios back to Windows 8.1 after upgrading it to Windows 10 and after the 30 day revert period. Works just fine. Why? Because I want to sell the laptop to someone in factory fresh condition without a trace of my Windows 10 stuff that might have carried over to it via Microsoft account syncing and the Windows 8 product key stored in bios is just as valid as it always was.

Just like my Windows 7 family product key that is still valid that I used to install Windows 7 on a second partition on my desktop computer to try to solve a hardware driver issue I was having.

You statement that the previous OS product key is invalidated either the minute Windows 10 activates or after the 30 day reversion period just isn't true. But if someone wants to believe you - it's their loss. If someone wants to go back to their previous OS and they try their old Product Key and it didn't work because your posted nonsense was true - well all they would lose is a couple hours of their time.

I have done clean installs of both Windows 7 and Window 8.1 previously upgraded to Windows 10 and they both activated just fine. Windows 8 product key stored in bios, and Windows 7 product key entered manually. Windows 8.1 was restored using ISO downloaded with the Windows 8 media creation tool and Windows 7 Home Premium was restored with the Microsoft genuine DVD from the retail package with the COA sticker.

Microsoft never has invalidated previous OS product keys upon upgrade, and they still are not. It is only the EULA that is violated if the previous OS product key/license is used at the same time the resulting upgrade license is being used, but Microsoft has never really enforced that by blocking product keys, nor are they currently enforcing it.

 

I have no idea what you are talking about. What is a "New Activation"? On some other hardware it had never been installed on? No, then. I've not bought any new hardware to test installing a legacy OS I've no interest in using.

I got the boring 0xC007C0008 key blocked error (twice) on 10 and just moaned at MS until they gave me a new key.

I have however restored both Windows 7 and 8 onto their original hardware and they were activated fine. If you want me to restore onto completely new hardware then I'm afraid I can't oblige as I don't have any and couldn't be bothered anyway..

Hali

 

Oh come on, now...you mean you wouldn't try it if they sent you a new Windows 10 from the factory laptop to try it on? ;-) I wish I had a dozen computers that never had Windows 10 on them to try a few things I am curious about.

 

Here's the deal. Party A says - nope won't work. Party B says - there's no problem doing it, I have myself, a couple of times. Party C needs or wants to do it for some reason.

Party C can just believe Party A and be out of luck. Or they can hope Party B is right and try it. If Party A turned out to be correct, all that Party C has lost is a couple hours of time. If Party B is correct - big win for Party C. Yes, I have been recently helping my daughter with her algebra homework.

So, dear reader....if you want/need to go back to your previous OS - the choice is yours.

 

No, I don't mean new hardware. I mean activation on the same PC, on which you already had it activated before. But: Activating it again! Another time. Not using an image, where Windows already is activated. But really activating it again.

Kari is saying, that the old OS was no longer activatable, but I don't understand how that fits to that other people could still use the previous OS without problems.

 

I can only provide my experience. I upgraded my 8.1 Pro to 10 Pro on my main system when it came out to force myself to use it and get used to it. This week I formatted and re-installed my 8.1 Pro and it activated over the internet with no issues.

 

Or how that would fit into the fact that computer manufacturers must provide support for the OEM Windows on the computers they sell, but are only required to support the operating system that the computer was sold with. In order for the manufacturer to fulfill their agreement with Microsoft, it must remain possible to return that computer to the OS that it came from the factory with - at least for as long the manufacturer has agreed to support it.

And probably thousands of users have done the same thing. Including myself, more than once.

 

No I was just keeping them for the case that 10 went down hill, but I'm keeping it. It defies physics, it's gaining speed going uphill*Eek. The thing is 10 runs better on my Win7 laptop than 7 ever did or will, and on my prior 8 machine it uses a lot les resources(CPU which is my bottle neck).

 

Well, Windows 10 works far better on my rMBP than the newest OSX version El Capitan (I dual boot). The only thing OSX is better at is battery life.

My Macrium backup for 8.1 is 17GB. For 10 it is 7GB (same software).

What can I say? I'm a convert.

Now if someone would just give me one of those Surface Books I'd be happy for at least 2 years (a HoloLens also perhaps 3 *Wink )