Microsoft chief executive Steve Ballmer got a lower bonus than last year's, partly for flat sales of Windows and his failure to ensure that the company provided a choice of browser to some European customers.
Mr Ballmer, who took over as CEO from co-founder Bill Gates in 2000, earned a bonus of $US620,000 for Microsoft's 2012 fiscal year, which ended in June, down 9 percent from the year before, according to documents filed overnight with the US Securities and Exchange Commission.
His salary - low by US corporate standards - remained essentially flat at $US685,000.
It is the third year in a row that Mr Ballmer has not earned his maximum bonus, set at twice his salary.
Microsoft's recent financial year was scarred by a massive $US6.2 billion write-down for a failed acquisition and lower profit from its flagship Windows system as computer sales stood still.
In the company's filing, Microsoft's compensation committee said it took into account a 3 per cent decline in Windows sales over the year, as well as "the Windows division failure to provide a browser choice screen on certain Windows PCs in Europe as required by its 2009 commitment with the European Commission."
The company's failure to provide a browser choice in Europe was an embarrassing setback for the software maker, which has been embroiled in disputes with European regulators for more than a decade and paid more than $US1 billion in fines for including its own Internet Explorer browser on Windows. It now faces further fines from a new investigation.