Skype on Windows 8.1 PC launching too slow?

As I said in the title, I'm using a Windows 8.1 PC, a Lenovo Yoga 2 Pro to be exact, and I started having problems with launching Skype. I double click the shortcut and even though Skype appears in the Task Manager, the main screen doesn't come up until 5 minutes or something. Everything was working fine and suddenly this problem occurred… Does anyone know why this happens or how to fix this? I'll appreciate any help.