Microsoft Corp. Chairman Bill Gates said Thursday he will gradually give up his day-to-day duties at the company to concentrate on the charitable work of the Bill & Melinda Gates Foundation. Gates, 50, will continue as the company's chairman after transferring his duties over a two-year period. "This was a hard decision for me," said Gates, who founded the world's largest software company with childhood friend Paul Allen. "I'm very lucky to have two passions that I feel are so important and so challenging. As I prepare for this change, I firmly believe the road ahead for Microsoft is as bright as ever."