FedeHW :
I found this page of the official Microsoft site where I can make a windows installer with a USB and just plug it in any new computer. My question is can I just use that and buy a oem key getting a cheaper way to get windows 10?
"I found this page..."
Yes, this, from Microsoft:
https://www.microsoft.com/en-us/software-download/windows10
This creates a bootable DVD or USB. For Free. MS has made available the ISO files for the OS's for free for many years. This is not a new thing.
The license key is what actually costs money. And from any reputable, viable retailer, it costs about the same. Somewhere between $80-$110 USD.
Find it much cheaper than that, either one of the major retailers has on sale, or it is not a valid...