How to prevent Skype from decreasing the volume of other applications in Windows 8.1

If you use the desktop version of Skype, you have probably noticed that every time you call someone or receive the call, Skype automatically reduces the volume of other apps, e.g. your music player. This can cause inconvenience if you do not plan to answer the call and you're listening to something important. Here's a simple tutorial which will allow you to change this behavior of Skype.