I have tested the tutorial. Now I preview my project everywhere in my house but it still take 7-10 mins.
I try it in FireFox, I'm on Windows 7, my processor is an Intel pentium G3450 and i have a Nvidia GTX 750 graphic card.
EDIT: 1 year ago, when i have tested the free version on my old computer(Vista), it took 5 second.
Solved:I'm stupid : construct 2 was just limited on a 5kb/s download/upload rate. I have just removed this restriction and now it takes 5 seconds. Excuse me for the useless post and please remove him.