Software giant Microsoft has announced record revenue of $12.54 billion for the last quarter of 2006, due in the most part to early order guarantees for Windows Vista and Office 2007 .

The revenue represents a 6 percent increase over the same period last year.

Operating income, net income and diluted earnings per share for the quarter were $3.47 billion, $2.63 billion and $0.26, respectively. Microsoft says this is "due primarily to the technology guarantee programs that were announced on 24 October 2006 for Windows Vista and the 2007 Microsoft Office release."

The company says that Xbox 360 and Microsoft SQL server - launched in the same period last year - have contributed around $1 billion of revenue growth.