Microsoft starts Windows 7.5 Mango rollout

Microsoft has started rolling out its long-awaited Windows Phone 7.5 update, more commonly known as Mango.

Described as Windows Phone 7's "largest and most feature-packed software refresh to date," Mango will be available to most customers within four weeks.

"I do want to emphasise that today is just the start. Our plan, as I'll explain in a moment, is to ramp up delivery gradually," said Windows Phone's general manager for customer experience engineering Eric Hautala, in a blog post.

This is a simultaneous, coordinated, global update that cuts across carriers, phone models, and countries.

"Today we're starting the roll out of Windows Phone 7.5 to more than 98 per cent of existing Windows Phone customers. This is a simultaneous, coordinated, global update that cuts across carriers, phone models, and countries. This time, almost everybody is going first."

Hautala explained that not everyone would be able to download the new OS straight away, largely because of the need to install new firmware on the manufacturers' side.

"If a problem comes to light, it's critical that we can isolate and fix it quickly. So we're deliberately starting out slow," he added.

"This week, we'll be making the update available to 10 per cent of customers. If everything looks good, we'll open up the spigot a bit moreto around 25 per cent. We'll hold there for one or two weeks, then quickly ramp up to 100 per centmonitoring quality the entire way."

When their update is ready, users will receive a message on their smartphone. They will then need to connect their devices up to Update Central in either Zune Software for PC or Windows Phone 7 Connector for Mac.

Microsoft announced a number of features it had "kept under wraps" until now, including tethering and a new Web Marketplace.