I live in dormitory and we have one WiFi router for 8 rooms. I have the worst signal so I plugged an Ethernet cable. Now I have great connection but after couple of days everyone started complaining that internet is slow and some times is not accessible at all. Could it be that I am "stealing" the WiFi. And if yes how can I resolve this issue without giving up the wire?
You mean you plugged into the router with a ethernet cable I assume.
The ethernet connection on most routers will have no impact at all on the wireless users. You need to think of the router as a wireless switch, a ethernet switch and the connection to the internet..wan.. You can in most systems transfer huge files between 2 ethernet ports and have no impact on anything else.
The key part that may be affected is not the wireless itself but the internet. You are sharing this with everyone else and if you are using too much it can "appear" to be a wireless problem when it is a simple out of capacity on the internet connection.
So for those who will be seeking answer in the future:
To resolve the issue i had to limit speed to 10% for myself. We are on 120 Mbps broadband with Virgin Media SuperHub. But Skype video calls (which I do a lot) were eating up the bandwidth.
Software that I used: http://seriousbit.com/netbalancer/