Skype has announced the launch of Skype 4.0 for Windows, calling it "the most distinctive new release in the company’s five-year history".

The company says the new version offers full-screen video calling, crystal clear call quality and is easier to use than ever before.

In addition, Skype users will find all of the features they have come to expect – free voice and video calls to other Skype users, instant messaging, SMS, as well as calls to landlines and mobile devices around the world at very low rates.

“Video calling has emerged as a very popular way for people to communicate online,” said Mike Bartlett, director of product strategy for Skype. “Whether it’s saying hello to your daughter at college or reading a book to your child while you’re away on business—video calling lets you have the conversations that make a difference and it really feels almost as good as being there.”

With the all-new Skype, people can experience the benefits of free face-to-face video calling. It’s now easier to start a video call and experience full-screen video, which makes conversations more intimate and engaging.

Additionally, a new built-in bandwidth manager ensures that consumers have the very best Skype video calling experience possible even on a low-bandwidth connection. If you have a fast enough connection (recommended 400 Kb/s or higher), a dual-core processor PC and a Skype Certified High Quality Video webcam, Skype delivers up to 30-frames-per-second High Quality Video.

Also call quality was substantially improved in the new version of Skype. The new audio codec achieves wideband audio quality using 50% less bandwidth than previously required. Moreover, it introduces super wideband audio that delivers crystal clear, richer and warmer sound to those using a compatible headset and a high quality broadband connection. The bandwidth manager interacts with the codec to adjust quickly to fluctuating bandwidth conditions to produce the most reliable sound.