Computer makes clicking noise when NOT loading

[Otte4]

My computer (an Asus) makes a repetitive clicking noise when it is not loading something such as netflix, youtube, antivirus check and so on. When a video is done loading or whatever it starts making the noise shortly afterwards. It starts clicking almost immediately when using Office programs, Spotify ect.
It begins about five minutes after I have turned on the computer if I do not access the internet and 15 minutes if I do.
My computer has always made the sound (almost 2 years) and I have sent it to be repaired once - they changed the hard drive, but it did not make a difference

Does anyone know what the problem is and how to fix it? It is really annoying to have a computer that sounds like a ticking bomb!

[patio]

Sounds like the "clik of death"...your HDD is failing...
Backup all you need immediately and quit using it til that's taken care of.

[Otte4]

But it has been a problem for almost two years - ever since I bought it, the harddrive has been changed, but the noise is still there? Nothing seems to be wrong with the computer other than the noise.