Acer-Manny said:

Hi minshyu,

We certainly try to have the best service and support experience for our customers, however, the repair time can depend or vary based in the authorized service center parts and availability. If you can please send me a private message with your case id number, I can forward your concerns to our contacts in your region, but please keep in mind that Acer community is not a direct portal to Tech Support or Customer service, this is a peer to peer support community where Acer users help other Acer users.

Thanks in advance,
Acer-Manny

Thanks for reply, Manny.

Yes, I know. It is a place to seek for help. And share information about Acer? Right?

Thu, I called hotline again. She said they already replaced HDD and were performing test.
Fri, I received SMS about my laptop is ready.
Today, i will go.

So they took 9 business days to replace a 1 TB HDD and initially they estimated 1 to 1.5 months.  This important information everyone should keep in mind.  

I will let you guys know after i get it back.

JackE said:

minshyu>>>I received SMS about my laptop is ready. Today, i will go.>>>

Sounds good so far. Did you go pick it up yet? What's the verdict? Jack E/NJ

Yes, I got it.

Here is timelines

May 21, I sent my laptop to service center
May 27, I called them to followup.  They confirmed HDD was broken.  They estimated they would take 1 to 1.5 months for replace.
May 29, I contacted TW hotline. They gave me HK hotline number.
May 30, I called them to followup.  They already replaced HDD and were performing some test.
May 31, I received a SMS.
Jul 1, I picked up my laptop.  D drive won't disappear after an hour.

Thanks and have a good day.