Steve Ballmer has been CEO of Microsoft since taking over from Bill Gates in January 2000, but his long tenure is drawing to a close.The tech giant said Friday that Ballmer has decided to retire within the next year, and the board has begun a process to find his successor. Ballmer, who has drawn criticism from investors for allowing rivals like Apple and Google to outrun Microsoft in mobile devices, is currently trying to transform Microsoft to focus on devices and services rather than just software."There is never a perfect time for this type of transition, but now is the right time," Ballmer said in the company's release. Gates, who will sit on the board search committee tasked with finding Ballmer's replacement, said Microsoft is "fortunate to have Steve in his role until the new CEO assumes these duties." Shares of Microsoft shot 8% higher in pre-market trading. About time! The revenge of Windows 8!