In 2002, the Desktop Platforms division accounted for 33 percent of Microsoft's total revenue. That percentage has been steadily dropping, and in fiscal 2013, the corresponding division (which now includes Microsoft's Surface hardware) was responsible for only 25 percent of the company's steadily rising total revenue. Server products, Office and other desktop applications, and cloud services increased steadily during that time.
Looking at operating income (what's left of revenue after you subtract expenses) tells a more interesting story.
From 2002 through 2004, Windows was the dominant contributor to Microsoft's profits, accounting for as much as 89 percent of total operating income. But that began changing in 2005 as those investments in enterprise software and cloud services began to pay off.