I have had a lot off help from this community so far, and I am going to give you all an other question to answer.
My computer Is pretty far from my router about 20 - 25 meters (and there are lots of walls between the router and my computer). There is no way to make this distance shorter. I always used an usb internet adapter but it would be of no suprise that this connection was slow and horrible. The worst problem is I think with the packet loss. I get download speeds of 200kb/s at most which Isn't the biggest problem but games (for example things like WoW and Rift.) Are not playable because of massive lagg and disconnects all the time. So I bought an PCI Wifi card. I bought the TL-WN851ND from TP-Link.
And now here is the really Issue. As soon as my computer starts up all other computers (and my ps3) their internet connection get scrambled. I don't know a better word to put it. Their connection turns horrible. They can't even open websites like google or it will atleast take 3 minutes to load it. The second I disable the Wifi card the connection of the computers and the ps3 turn back to an solid connection.
How can my Wifi PCI card do this and how can I fix this?
Once the pci wifi card is disabled the other computers have a fine connection. Not great seeing the distance. But good enough to stream videos or play said games. the usb adapter on my computer that which I went back to using gives fast enough internet to post this topic and watch some low res vids. but doesn't allow me to do anything more than that. Once the wifi PCI-card is enabled This computer will have the same horrible connection as the other computers around it. So it also scrambles itself or something..
If anybody can help me trying to fix this I would greatly appreciate it!