I decided to upgrade my Motherboard, Graphics Card and Hard Disk to SSD.

Here's my current specs:

MSI Z97 Gaming 7 Motherboard
Intel Core i7-4790 3.60GHz 1150 LGA Socket
16 GB of RAM
ASUS NVIDIA GTX970
Samsung SSD 250GB 850EVO
Windows 8.1

The situation :

When I play FFXIV, it randomly crashes. Sometimes the sound remains but I can't open Task Manager, the desktop completely crashed. There are times that the whole system restarts or just shutdown.

Trial and Error :
1. I tried to reduce resolutions and graphical settings of the game.
2. The NVIDIA graphics driver is up-to-date and currently on version : 347.88
3. I tried to re-install my graphics driver.
4. I tried to check background applications and firewall then applied authorization to ffxiv.
5. Tried to replug DVI adapter.
6. Updated Windows 8.1 via Windows Update.
7. I tried to play different game : Dota 2; but Dota 2 didn't crashed and ran smoothly.

What I am trying to do now :
1. Re-installing FFXIV. So far the updater(patch) is si slow and sits 0.17Mbp/s and consistently going down from 3.6Mbp/s. (13.8GB of patch)

I tried my best and consult Google for solutions and none of the results were effective. While I do the reinstallation, does anybody here can help me with my problem?

PS: I will update this post after I re-install the game.