Microsoft piracy check comes calling

Microsoft is taking its fight against software piracy to the desktop.

Starting Tuesday, the software maker will push out a test tool that checks whether the copy of Windows a PC is using is properly licensed. It will be sent to millions of people in the United States, United Kingdom, Malaysia, Australia and New Zealand, Microsoft said Monday.

Following download and installation of the "Windows Genuine Advantage Notifications" tool, users of a pirated copy will see alerts at startup, login and during their use of the operating system. The alerts read: "This copy of Windows is not genuine; you may be a victim of software counterfeiting."

Those who use a legitimate copy of the software won't see any messages, Microsoft said.