Install windows on a brand new SSD with product key

Hi,
Currently I'm using windows 10 on a HDD on my desktop.
The desktop used to run windows 8, but I upgraded it. (so the product key is used)

Using Belarc Advisor, I got my Windows 8 product key.
I have a brand new SSD here so I want to upgrade to this SSD.

However, the HDD is bigger than the SSD and I can't shrink the HDD to be smaller than the SSD.
Hence, I'm looking for a way to download Windows 8 iso file and use that iso file to install Windows 8 on my new SSD.

Is it possible to download a Windows 8 iso file with a used Windows 8 product key.
If the answer is yes, how do I do it?

Create installation media for Windows 8.1 - Windows Help


But, do you want Windows 8, or Windows 10? Just install Windows 10 if that is what you want to end up with.

NavyLCDR said:

Create installation media for Windows 8.1 - Windows Help


But, do you want Windows 8, or Windows 10? Just install Windows 10 if that is what you want to end up with.

I want to get windows 10 in the end, but I only have windows 8 product key.
How do I get the windows 10?

Anonymous123 said:

I want to get windows 10 in the end, but I only have windows 8 product key.
How do I get the windows 10?

Either here:
Windows 10

Scroll down to download tool now. Then make installation media for another PC option.

OR

Tech Bench

Since you've had Windows 10 as an upgrade on that computer before, just click "I don't have a product key" or "skip" or "do this later" when asked for a product key. Install the exact same version/edition of Windows 10 you had before and it will activate by retrieving a digital entitlement from Microsoft activation servers via the internet.

The latest build (10586) of Windows 10 will also accept a Windows 8 product key to activate it, but you shouldn't have to enter one.

NavyLCDR said:

Either here:
Windows 10

Scroll down to download tool now. Then make installation media for another PC option.

OR

Tech Bench

Since you've had Windows 10 as an upgrade on that computer before, just click "I don't have a product key" or "skip" or "do this later" when asked for a product key. Install the exact same version/edition of Windows 10 you had before and it will activate by retrieving a digital entitlement from Microsoft activation servers via the internet.

Alright, thanks!