One sure fire way to boost the number of people using your software is to give it away for free. That's the approach Microsoft is reportedly taking in creating a new version of their latest OS, tentatively dubbed Windows 8.1 with Bing.

The software will come bundled with select Microsoft apps and services according to sources familiar with the company's plans as reported by The Verge. It will be marketed as a low-cost upgrade option for those currently running Windows 7 although a target price point wasn't mentioned. The Redmond-based company may license the software to PC makers for devices in the sub-$250 price range.

In addition to growing its Windows 8.1 user base, Microsoft is also hoping the experimental initiative (and others like it) will help monetize their cloud services and apps like Bing, OneDrive and Xbox Music. But perhaps the real reason that Microsoft is looking into a freebie version of Windows is to combat the growing threat of Chromebooks and Android.

Another such experiment is the consideration of low-cost or free versions of Windows Phone, we're told.

Sources say we can expect to hear more about Windows 8.1 with Bing and plans to merge Windows Phone with Windows RT during Microsoft's annual Build conference. That event is scheduled to kick off on April 2 from the Moscone Center in San Francisco and run through April 4.