What should I expect to see - 3 to 5 GB ?
I couldn't download the ISO yesterday (as my network modem wasn't working properly ) but it should be around 3.5 GB. I'll let it download this night.
I haven't tested, but rather than selecting the "update", maybe the "iso" has the option to update an already installed Windows 7 or 8. So it will be more efficient to work like that (also for the future use).
Because the activation of Win10 is done based on the activation of Win7 or 8 if you're planing to change some hardware in your system the best is
-a) to that change before updating to Win 10, or,
-b) to install Win 10 from zero and use it unactivated until the changes are made (which will require to go back to Win8.1, activate Win8.1 with the new hardware (in generally it works, but it can also kill the licence), update to Win10 activate it again, and then install Win10 from zero. I like more clean installs
![Big grin :D :D](https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f600.png)
)
For those who want to use
method b) the KMS keys for Win10 are here (more exactly those for Prof and Edu; they will allow you to install Win10 "iso" version, but not to have it activated. Of course, if you have a Win10 licence you can change it later directly in Win10):
https://technet.microsoft.com/en-us/jj612867.aspx
...to be corrected if I'm wrong.
Personally I think I'll go with b) as I planed to add an SSD, and the price for Samsung EVO 850 500GB is today as low as 150 € (but I think it will become even cheaper). Of course, I'll make a cold backup of my actual 8.1 so, it will be easier to go back when I'll activate my licence with the new hardware.