WASHINGTON?Microsoft founder Bill Gates took the stand Monday for the first time in his company’s epic antitrust case, testifying the penalties being sought by nine states would undermine the Windows software used by millions of Americans.

Gates opened his long awaited courtroom appearance with a computer-generated slideshow. He demonstrated how the Windows operating system would stop functioning if components such as the Microsoft Explorer Web browser are removed as the states have proposed.

Gates also expressed Microsoft’s fear that if the company were forced to translate its Office business software, other companies could effortlessly create Windows clones.

To show the companies that could create clones, Gates named five companies that have helped the states’ suit: AOL Time Warner, Sun, Gateway, Novell and Oracle.