I hardly remember any desktop computer of mine that's never made any loud noise by the fan at some point.
Often times, the case fans, sometimes, the power supply fan, and occasionally, the cpu fan.
Thanks to a good tip, I found a very effective way to resolve the situation.
Solution:
Apply the following in order to back of fan (The side that has sticker covering, remove sticker, remove rubber cap)
1. a little pinch of Graphite powder
2. Motor oil (3-In-One SAE 20 Blue brand)