Download Skype http://www.skype.com/intl/en-us/get-skype/on-your-computer/windows/

Calling other people on Skype is free so you can talk whenever you want to – not just on special occasions. Call to check in with mum when you’re travelling, give your partner a goodnight kiss via video call when they’re away on business, or use it for your regular calls and catch ups. And, if you know people who don’t use Skype you can call them too at really low rates. Get here http://www.skype.com/intl/en-us/get-skype/on-your-computer/windows/