ok 1st i am a beginner in the pc net stuff...be gental please..okies my son has just brought a new pc that he has upstairs connected to our BT router via wifi (router is downstairs) we use another pc and ps4 both (downstairs) connected via wired... now when my son starts his pc up our net drops from 3.8Mbps to 1.7Mbps.......... if just my pc n ps4 are connected no drop in speed, even if the xbox is connected via wifi no drop in speed....any idea why his pc is dropping our speed by so much.. this is b4 he even gets on to the net to play any game or surf..when he starts up his pc we cant load pages or play on the consoles as they keep dcing or timing out..