Microsoft was too slow to react to the emerging mobile market, outgoing CEO Steve Ballmer has admitted.
Speaking to investors, as reported by the BBC, Ballmer said the computing giant was too focused on developing its Windows operating system for PC, rather than taking an early slice of the mobile market.
The Microsoft boss said Windows Phone had “almost no share” in the mobile space, with Apple’s iOS and Android, used my companies such as Samsung, dominating.
"I regret that there was a period in the early 2000s when we were so focused on what we had to do around Windows that we weren't able to redeploy talent to the new device called the phone," said Ballmer.
"That is the thing I regret the most. It would have been better for Windows and our success in other foreign factors."
Microsoft first released the Windows Phone in 2010, three years after Apple released its first iPhone, and two years after Google launched its Android OS.
In an effort to gain more traction with developers, Microsoft recently lowered the development fee for Windows Phone following a successful summer promotion.
Developers can now sign up for the Windows Phone Dev Centre for £15 ($19).