Ballmer's Bonus Shrinks on Weakness of Windows SEATTLE - Microsoft's board of directors has again penalized the company's chief executive, Steven A. Ballmer, for the company's performance by giving him a smaller bonus than he was eligible for. In a proxy filing with securities regulators on Thursday evening, Microsoft said that Mr. Ballmer received 39 percent of the total annual bonus he could have received this year. Microsoft singled out an 18 percent decline in the operating income of its Windows division and a $900 million charge related to the slow-selling Surface tablet as reasons for giving Mr. Ballmer a smaller cash award. Under the company's compensation rules, Mr. Ballmer was eligible for a bonus ranging from 0 to 200 percent of his base salary of $700,000, meaning he could have received up to $1.4 million in bonus money. Instead, he received $550,000, or 79 percent of his base salary. He received 91 percent of his base salary as a bonus last year, when he was also eligible for a cash award of up to 200 percent of his pay. Weakness in Microsoft's Windows division and the slow progress of its Internet unit were among the reasons Mr. Ballmer's pay was docked then. The bonus given to Mr. Ballmer, who announced in August that he would retire from Microsoft within 12 months, is mostly symbolic. Mr. Ballmer's salary is low by the standards of big company leaders, and he does not accept new stock awards as part of his compensation. In short, he does not need the money. As an early Microsoft employee, Mr. Ballmer holds more than 333 million shares of Microsoft, or just under 4 percent of the company. His stake in Microsoft was worth $11.3 billion at Thursday's closing share price.