While the announcement of Windows 10 included word that the upgrade to this OS would be free, not every user will have that opportunity. The opportunity to attain this operating system at no cost is limited. Only those who have Windows 7 or 8.1 "Pro" editions - not those with the "Enterprise" editions - will receive this upgrade for free. This push also only exists within the first year of release of the OS. You'll want to read this fine print before you proceed to the "go" button.