After maintaining a "market perform" rating on Microsoft for the past three years, one analyst has finally changed his tune and upgraded the stock to "outperform."

On Tuesday's episode of "Fast Money," FBR senior analyst Daniel Ives explained why he thinks now is the best time to own Microsoft.

"You finally feel like there's a pilot on the plane after 10 years of pain," he said, reflecting his belief in CEO Satya Nadella's vision.

Part of that vision, according to Ives, centers on Microsoft's Office 365 and cloud strategies.

"Everything we see in cloud really signifies a turnaround," he said. "We could view a $4 billion to $5 billion revenue stream."

Nadella's mobile strategy, including the decision to offer free Windows on mobile devices smaller than nine inches, could be another positive catalyst, Ives said.

"What he's starting to do on mobile, and the turnaround, we could see an incremental 40 cents to annual earnings, and that gets us incrementally positive on the name," he said.

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Ives' boldest call focused on Microsoft's future in the handset market. "I think they could go from 2 percent market share to 10 percent. … Nokia is the X variable," he said.

Microsoft was the second-best performer in the on Tuesday, helped along by FBR Capital's upped rating and price target.