President Hu Jintao called for closer ties between China and the US, saying that while his country's fast growth has made problems "hardly avoidable", it presented significant opportunities for trade partners. Hu made his remarks at Boeing's Seattle headquarters and used the company, which recently secured an order from China for 80 Boeing 737s, as an example of mutually beneficial Sino-US ties. He also reaffirmed a pledge made the previous day to improve the protection of intellectual property rights in China. His original comments on IPR came during a highly unusual impromptu question and answer session with reporters after he had been given a tour of Microsoft's Seattle headquarters by company chairman Bill Gates. "Bill Gates is a friend of China, and I am a friend of Microsoft," Hu said. With 90% of China's Windows users running their systems off pirated software, Microsoft has struggled to make a significant impact in China. Beijing recently responded to US pressure over IPR by introducing new regulations intended to ensure that computers sold in China come pre-loaded with licensed software.