You can download the ISO and/or create a USB drive using this tool: https://www.microsoft.com/en-us/software-download/windows10
However, from doing some searching I think that if you currently have W7/W8/W8.1 you can't use the keys directly during a clean install.
Basically what you have to do is do an upgrade on your existing machine, then the hardware info is saved against the activation for W10 so you can then do a wipe and a clean install on the same machine (not entering a key during installation) and it should activate normally after that as it will recognise the machine.
What this doesn't give you is a proper Windows 10 key for future installations on different hardware and it's not clear what hardware changes would lead to a failed re-activation. Plus this doesn't seem like a great process for those who have purchased a Retail version of Windows 7/8/8.1 as those are meant to be able to be moved from machine to machine without issues.
I think this process might be ok just now when people are upgrading existing machines but will lead to issues down the road if MS don't issue a proper license key for W10 for those that are upgrading. Alternatively maybe there is a way to extract the key once you have done the W10 upgrade, but I suspect there will still be activation issues if you change too much hardware or the machine itself.
However, from doing some searching I think that if you currently have W7/W8/W8.1 you can't use the keys directly during a clean install.
Basically what you have to do is do an upgrade on your existing machine, then the hardware info is saved against the activation for W10 so you can then do a wipe and a clean install on the same machine (not entering a key during installation) and it should activate normally after that as it will recognise the machine.
What this doesn't give you is a proper Windows 10 key for future installations on different hardware and it's not clear what hardware changes would lead to a failed re-activation. Plus this doesn't seem like a great process for those who have purchased a Retail version of Windows 7/8/8.1 as those are meant to be able to be moved from machine to machine without issues.
I think this process might be ok just now when people are upgrading existing machines but will lead to issues down the road if MS don't issue a proper license key for W10 for those that are upgrading. Alternatively maybe there is a way to extract the key once you have done the W10 upgrade, but I suspect there will still be activation issues if you change too much hardware or the machine itself.
