Microsoft is reportedly developing a free version of its Windows 8.1 operating system in an effort to drastically increase the OS user base. Dubbed Microsoft 8.1 with Bing, the OS could be offered to OEMs or end users as a means to provide customers with access to important Microsoft services. According to a report from The Verge, which cites unnamed sources, Windows 8.1 with Bing could be made available as an upgrade to Windows 7 users.