I don't think it's a network problem... I've got 2 other computers connected right now (1 Pc + 1 Laptop) and none of them seem to have problems...
So I'm just thinking it's a PC problem...
#Edit#
I've updated the controller driver (or at least I downloaded the updater from nvidia but it seems like nothing happened)
Now trying to reset my router to factory settings
It didn't work... I'm starting to get desperate...