Google Inc. previewed the first laptops running the company’s Chrome operating system, machines that will go on sale next month as part of Google’s challenge to Microsoft Windows.

The “Chromebooks” use operating-system software based largely on Google’s Chrome Web browser.

The laptops are designed primarily to run Web-based applications, including word-processing and games. Because they rely on Web-based apps, the Chrome devices boot up in eight seconds, the company said. The laptops, however, will have limited capability when offline.

To ensure that Chrome laptops always stay online, Google said Verizon Wireless will provide free wireless Internet connectivity (up to 100 megabytes of data a month).

Google will sell the computers for $28 a month to corporate customers and $20 a month to educational institutions and governments.