Any possible reason why my CPU always crash and auto-restart when I open Starcraft?
But once rebooted, SC would work

No Idea, but I guess
A virus or maybe a hardware-graphic-card bug?

Try reinstalling starcraft if you haven't already.

Try scanning your computer for viruses, spyware, and adware (Note that not all programs scan for all three of these.) If that doesn't work, try installing SC on another computer: That will at least tell you if the problem is on your computer or if something is actually wrong with your copy of SC.

Also, maybe you could use Farty's Downgrader to downgrade to a version that didn't give you the error and see if that helps... If it does, connect to Bnet to upgrade back to the current patch and see if you start getting the error again. If downgrading fixed it but upgrading broke it again, then it's probably a hardware problem. (Also, I once broke one of my MPQs somehow... You might have done the same, in which case downgrading and re-upgrading might fix it.)

Update your video driver. I had the exact same problem before, and that's how I fixed it.

How to do so?

Download the driver and update it, lOL!

I just found it works on an other session, but not the principal one
Wth? :'(

Okay, solved
In fact, it is the SysFader that would make my computer crash. If ever you have this problem too, right click on your desktop, select properties, go under "Display", "Effects" and UNcheck all the 4 first boxes.