Tango, has raised $42 million aimed at rapidly growing its workforce to compete with ooVoo and the industry leader,Skype. Tango has announced that it plans to bring its video calling service to PCs sometime later this summer. The desktop video chat service will be a Windows-only affair, and will remain free of charge and you won’t need to register to get your videophone on.

The Series B funding round was led by Draper Fisher Jurvetson and includes existing investors. It includes $8.7 million raised in a convertible note that was revealed through an SEC filing earlier this year. With the latest round, Tango has raised a total of $47 million since being founded just 18 months ago.The round also gives it extra cash to extend its video chat app beyond just mobile devices, to reach some 1.5 billion potential desktop users.

“We have an incredible opportunity ahead of us and we are growing at an unprecedented rate,” said Uri Raz, cofounder and CEO of Tango. “There are 1.5 billion PCs in use worldwide and 95 percent of the world’s computers run Windows. With this launch, we are well positioned to reach our goal of 100 million customers by this time next year.”

Tango launched with a mobile focus but is gearing up to start working on PCs.It currently has about 18 million users on mobile devices. The new app will mirror its existing mobile apps both in form and function, allowing users to be simultaneously logged into their accounts through multiple devices.