Microsoft Corporation has been tarred as an illegal monopoly and a copycat. Its flagship Windows operating system gets knocked for its security holes and user-unfriendly quirks. So what is the world’s dominant software company doing? Betting billions that its next generation of Windows, code-named Longhorn, will be the breakthrough technology that quiets its critics.

Corbis Corporation, a photography-archiving company owned by billionaire Bill Gates, filed a federal lawsuit against Amazon.com and several partners, alleging copyright infringement.