Eight officials from Japan's Fair Trade Commission entered the Japan offices of Microsoft this morning as part of an investigation into possible anti-competitive practices.
"The FTC officials are conducting an investigation regarding provisions in Microsoft licenses with PC manufacturers," said Aki Araki, a Microsoft Japan spokeswoman. "We are confident that our practices are consistent with Japanese law."
A team from Microsoft is continuing to help the FTC officials with their investigations.
Previous probes in the US and Europe have focused on whether Microsoft illegally maintains its monopoly in PC operating systems through restrictive licensing agreements with PC makers.
Local media sources quoted unnamed officials as saying that the investigation focuses on the licensing for Windows XP. In 1998, Microsoft was warned by the FTC to stop engaging in anti-competitive business practices, but the company escaped punishment.
Japan is the world's third-largest market for PCs after the US and China.
David Legard writes for IDG News Service