Here's some info on the "free" upgrade I tracked down. Be wary of anything "free" especially from Mikrosoft.
you will get upgrades automatically whether you want them or not (you can't turn them off.) All your old system files will be automatically deleted after 30-days. That means if you don't like Windows10 you can't go back to your old system after 30-days because it will have been erased automatically by windows10. If your malware software expires Windows10 will erase it automatically and install Microsofts own version.
