videos on google chrome and windows do not play right away

So I have a Windows 8 and whenever I go on YouTube on Google Chrome (it's not only YouTube that does this) the video loads completely but the video doesn't start for a whole minute or even more. It is not my internet connection because when I want to watch a video on the computer itself it does the same thing! Also when I want to listen to music on iTunes it does the same. Sometimes if i pause the video it's gonna take a whole minute to play again.

Please help it's starting to bug me. thanks