[Deepak]

Hi. I have been an Insider since the very first Insider build was released. I had installed each and every build first being on the Slow ring and the on the Fast. I had upgraded from a genuine Windows 8.1 Pro.

When the final RTM build TH1 Professional 10240 was released to Insiders ahead of schedule, I readily installed it and my machine was permanently activated at that time. The product key used was a generic one ending in 3V66T. Many of you may be knowing this.

Today, in fact just now, I formatted my system partition and installed a clean copy of Windows 10 Pro from USB which I had created using the Microsoft Creation Tool. When the setup asked me for a product key, I entered the same generic key as stated above. But now when I go to the Settings, it says the key doesn't work and hence, my machine cannot be activated. I signed-in using my Microsoft account before using the PC.

What the heck! I am an Insider. And didn't expect this to happen. What should I do next? Would the machine get activated itself after some time? Or should I try something different? Please help me out and guide me ahead. Thanks in advanced.

[Deepak]

Anyone?? Please. 😓

[instantk]

Are you sure u are installing it on same partition as before? Try entring your old windows 7/8 keys.

I clean installed windows 10, but i didnt format the system partition deleting all non windows essential folders before... I think formating probably did the mess..you should have simply inserted the USB when your old build was on, click on install and restart., with deleting personal data option checked during install

Now you can try to restart the installation process proceeding with delete existing data when encountered during install process...maybe then it might be able to activate using key

[Deepak]

Are you sure u are installing it on same partition as before? Try entring your old windows 7/8 keys.

I clean installed windows 10, but i didnt format the system partition deleting all non windows essential folders before... I think formating probably did the mess..you should have simply inserted the USB when your old build was on, click on install and restart., with deleting personal data option checked during install

Now you can try to restart the installation process proceeding with delete existing data when encountered during install process...maybe then it might be able to activate using key

I have three partitions and all of them are uniquely named. I am sure I formatted the right partition as other partitions are intact.

I wanted a clean copy of Windows 10 on my laptop as the previous one used to behave insanely like disconnecting the WiFi suddenly, the Mail never synced, it wouldn't let me open my own user files like Documents or OneDrive folders, etc. So, a partition format was required.

[instantk]

I have three partitions and all of them are uniquely named. I am sure I formatted the right partition as other partitions are intact.

I wanted a clean copy of Windows 10 on my laptop as the previous one used to behave insanely like disconnecting the WiFi suddenly, the Mail never synced, it wouldn't let me open my own user files like Documents or OneDrive folders, etc. So, a partition format was required.

I guess it might be internet connectivity issues while activation.
Try connecting an ethernet cable before activation. Windows10 can be used without activation for 1 month..if you dont have ethernet, make sure wifi is connected and working.
Also, try to opt in/ out of get insider builds from settings menu and then try activation.

[_Emi_]

When you clean install, you don't have to enter any key. that was your problem and why it told you it didn't work.
They activation is managed by your hardware, not a key. so if it detects your hardware on their magical database, they would activate your Windows. but if you add a key, how is it suppose to activate you?

It asks you for a key twice and you only have to skip it, it was on the FAQ. and it has worked for me 5 clean installed I have made.

That was the mistake I noted on your explanation. you never skipped the key enter thing.

[Nopea]

Ill borrow this topic if you dont mind. I updated 8.1 to w10 and activated it. Then performed clean install. All worked fine. But couple days ago i bought new mobo, processor and ram and did clean install straight. Now w10 wont activate so should i revert back to 8.1 and start all over ?

[_Emi_]

Ill borrow this topic if you dont mind. I updated 8.1 to w10 and activated it. Then performed clean install. All worked fine. But couple days ago i bought new mobo, processor and ram and did clean install straight. Now w10 wont activate so should i revert back to 8.1 and start all over ?

Well, you changed everything so it's counted as a new computer, someone said just motherboard bridges are counted for the activation, someone said he changed the processor and nothing happened, but changing the motherboard would cause for sure the deactivation.

so you could go back to Windows 8 upgrade, if it complains about the key, you have to call Microsoft and explain them what happened, and you have the same computer but you changed motherboard, they will be nice to you I am sure.

you could also do the same, go to windows 8, but on a different harddrive or partition or sdcard or anything where you can install WIndows, upgrade to windows 10 and activate your new hardware. once you do that, if you go to the clean installed Windows 10, it should say activated because your hardware would be recognized. you can do both, I mean if you clean installed and installed programs and all, and you don't want to go back to windows 8 to go to 10 and then clean install and install everything, you can just use a second partition or an external harddrive or something, just to register your hardware.

[Deepak]

When you clean install, you don't have to enter any key. that was your problem and why it told you it didn't work.
They activation is managed by your hardware, not a key. so if it detects your hardware on their magical database, they would activate your Windows. but if you add a key, how is it suppose to activate you?

It asks you for a key twice and you only have to skip it, it was on the FAQ. and it has worked for me 5 clean installed I have made.

That was the mistake I noted on your explanation. you never skipped the key enter thing.

So, what if I perform a clean install again but this time skip entering the product key? I doubt if it would work.

[iamtim]

I updated 8.1 to w10 and activated it. Then performed clean install. All worked fine. But couple days ago i bought new mobo, processor and ram and did clean install straight. Now w10 wont activate so should i revert back to 8.1 and start all over ?

I've heard it said that in those situations, if you call in to Microsoft for activation, they'll activate it for you.

[iamtim]

So, what if I perform a clean install again but this time skip entering the product key?

The Windows 10 activation key is machine and account based. If that machine had a valid Windows 10 activation key (which is usually obtained via upgrading a legitimate, activated copy of Windows 7 or 8.1; I'm not sure how that happens for Insiders) then doing a clean install and skipping the requests for a CD key should result in an activated Windows 10, once the new Windows 10 installation is able to connect to the internet.

[_Emi_]

So, what if I perform a clean install again but this time skip entering the product key? I doubt if it would work.

You said you upgraded with a valid Windows 8 key, that means when you uploaded insider build (unless you clean installed before) it was carrying that key until RTM.

so if you did the upgrades well and never wiped the windows 8 key, it should activate because your hardware was activated so every clean install you make would automatically activate based on your hardware Like iamtim says. then you can go and get insider builds from settings.

You said you were activated from 8 to 10 the first time. that's why I am sure if you skip the key you will get activated because you were already activated. it's on FAQ site. about skipping if you already took the free upgrade offer. after that I have clean installed windows like 5 times and it always say activated.