How to customized icons on certain folders on Windows 7?

Hi Guys,
I wanted to customized the icons on my folders but it is not as easy as I thought it would be, I'll explain. For example, Documents, My Music, My Videos & My Pictures are all Windows default folders so they're difficult to modified! When I right click on one of these folders, under the "Customize Tab", there is none option to change the Icons but I know it can be done.

The new folders i created myself like for example, my games, well all I did is right click on the folder itself and click Properties. After that, I click on the "Customize Tab", I chose "Change Icon" and I browse for my new icon that I want to add instead of the old one.

Now, my question is, do you have an idea on how to customized the Icons on these Folders ?

Thanks in advance,

Yannik A

Are you willing to use 3rd party software? If so, you might take a look at this list of apps that can customize the system icons for you:
System Tray Icons at Customize Software Informer.

Wow, thanks a lot guys, I honestly appreciated very much!