How do I find the product key for Windows 8.1

Original title: Product Key

I downloaded Windows 8.1 (free) from the Microsoft web site. My understanding was that in doing so, a new product key would be generated. I do not know where/how to find the new product key. Can someone help me out with this? Was I mistaken and do I use the product key I have for Windows 8?

MY P.C. IS AN ACER DESKTOP WAS RUNNING WINDOWS 8  WHEN NEW  (NOW)

windows 8.1 was put on by a member of staff at p.c. world where I took it to get

repaired?(It was under contract policy with them 

I had windows 8 on when it went in TO THE SHOP ?

NOW I have windows 8.1 on it  the problem is I have a tower desktop i paid for from 

p.c. world already set up and running windows 8  by them?

the point is I got no start up disk with my p.c. only a U.S.B. STICK with startup information.

so if I wish to get somthing to update for my windows 8.1 it says put your product key

number in i cannot because I have NO PRODUCT KEY NUMBER?

What I am asking you is can your help me find my key number it must be on my p.c.

some where can you point me in the right place to find it

Download and use "Keyfinder" it will produce your computer's product key needed to download any windows product or revert back to Win. 8 like I did. See my previous posts on this thread.

Original title: Product Key

I downloaded Windows 8.1 (free) from the Microsoft web site. My understanding was that in doing so, a new product key would be generated. I do not know where/how to find the new product key. Can someone help me out with this? Was I mistaken and do I use the product key I have for Windows 8?

thank you help o.k.

No, the upgrade does not and never would generate a new key. The old key is still effective after the upgrade.

However essentially that key would not authenticate 8.1 so to reinstall you had to stage the process.

With thanks to Andre this link will allow you download a specific image which using a full 8.0 key allow you to install 8.1

http://windows.microsoft.com/en-us/windows-8/create-reset-refresh-media

I have only tested that full license and clean install. I have not tested an upgrade key or process. It very likely will not work with the key extracted from a system preinstalled at the factory either. That key has no known use.