My computer was so loud. Well I have ran into this problem before. Last time it was an easy fix and I simply put duct tape on the fans to stop them from making that loud noise and insulated the harddrive so the sound couldnt get out.
I did this again but this time I took it up to the next level. There are fans on my power supply that create noise so I filled that up with Rubber to stop the fans from making that noise. Next I stuck a nail in the video card fan to stop that sound and covered all the holes in my tower with duct tape. Now with all the holes covered I could fill it up with expansion foam.
The only problem I had was that the expansion foam puffed up so the cover doesnt go on now. I put the PC in the oven for afew to let the foam melt down.
Its been 1 minute now and its running perfect. Just wanted to help anyone with sound problems. Your welcome to all those I helped.