Cant argue with free.
True.
Well, strictly speaking, one -can-, but it's kinda dumb. Some people do. :-)
'Course, it depends on whether the free thing is what you want. I once knew a girl who, as they say, couldn't even give it away...
Microsoft is determined to have everyone get Windows 10 as they will in the future charge you each year for it like they are for Office. If you don’t pay they will block you from using it except to get your files off the pc.
Once they do this I suspect free Linux will become more and more popular.
Office charge:
https://products.office.com/en-us/buy/office
Forbes article says Windows 10 free for existing device... however
http://www.forbes.com/sites/gordonkelly/2015/06/17/windows-10-free-for-1-year-what-happens-next/
Excerpt: On multiple occasions this year Microsoft has come out and said it sees itself as a services company moving forward and that it views Windows long term as a subscription service, not a buy once platform as it has been up to now.