windows 10 will not be a mandatory download as yet but my view is windows 8 will run for a term of 10 years, according to Microsoft news. even then it will not be mandatory. my personal views are that window 8 will eventually become redundant, then those wishing to stay with Microsoft will have to move to windows 10. also I expect that Microsoft will eventually make it a yearly subscription as the have with MS office, why do you think they are giving it away, you don't get anything for nothing in this world