Former Microsoft CEO Steve Ballmer has finally spoken out about his last few years at the software giant. In an interview with Bloomberg TV, Ballmer recounts his history at Microsoft and his relationship with Bill Gates over the year, and also blames Surface hardware and phones for the pair falling out.

"When I became CEO we had a very miserable year," admits Ballmer. "Bill didn't know how to work for anybody, and I didn't know how to manage Bill. I'm not sure I ever learned the latter." Ballmer says his life "changed a lot" in 2008 when Bill Gates left the company. Ballmer said he did some of his "very best work" after Gates left, citing Bing, Office 365, Microsoft Azure, and the company's push into the hardware business with Surface.

"We've kinda drifted apart," reveals Ballmer in the interview. "Microsoft was kind of the thing that really bound us... since I've gone we really have drifted a little bit." Ballmer blames two things for the pair falling out: a difference of opinion and a brotherly relationship that had good times and bad. "There was a fundamental disagreement about how important it was to be in the hardware business," says Ballmer. "I had pushed Surface, the board had been a little reluctant in supporting it, and things came to a climax about what to do about the phone business."

Ballmer claims he would have moved into hardware quicker

Ballmer claims he would have moved into the hardware business faster, and suggests "a separation of chips, systems, and software wasn't going to largely reproduce itself in the mobile world" like it did with the PC. However, Google's Android operating system took over that separation of chips, systems, and software, and has managed to secure the majority of mobile share as a result. "We should have been in the hardware business sooner, in the phone case, and we were still suffering what I would call some of the effects of our Vista release of Windows," admits Ballmer. The former CEO has previously referred to Vista as his biggest regret at Microsoft, because the OS "sucked up a huge amount of resource for a much longer period of time than it should have because we stumbled over it."

On the subject of Microsoft's failed Nokia acquisition, Ballmer admits the board disagreed with it initially and "then came back and said the company should go ahead even though I had decided to leave." Microsoft has laid off thousands of employees and written off the majority of its $9.5 billion deal to acquire Nokia's phone business. Despite this, Ballmer still thinks the deal could have worked. "I think it was, if executed in a certain way it made a lot of sense," says Ballmer. "The company chose to go another direction and that's the decision the company made."

Ballmer is still happy about Microsoft's stock

Microsoft recently reported rising revenues thanks to Office, Surface, and its cloud services. The company's stock jumped above $60, for the first time since December, 1999 as a result. Ballmer is still one of the largest holders of Microsoft stock, so he's understandably excited to see it doing well. "I see the stock price flying sky high and all you can say is the market certainly agrees with the direction Satya is taking the company and I'm super excited about that."