What is the relationship between Windows 10 and Microsoft in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

For starters, Microsoft is offering a free Windows 10 upgrade for existing Windows users, so I suspect most PC owners will simply download the free operating system and keep their current machines.

Answer: developer