Hello Phake,
Tenacious problem you have there. Luckily you already have eliminated some factors, like your PC also does not network in your friend's room. Considering all the things you have done so far, my next step would be to invite a friend or relative over to your room, and try out the network connection. Did you do that already? Doing so will tell you two things:
1. your friend's computer has network in your room. Root cause of problem probably with your PC
2. your friend's computer does NOT have network in your room. Root cause possibly in your room connection.
Considering your story, it is very probable that another computer that is known to work on another network connection will work with your network connection.
Second: Does your Operating System (windows I presume) recognise your LAN Adapter (the network card)?
Third: Open a DOS/Terminal box on your PC, and at the prompt enter the command: ipconfig /all
Do a printscreen, and save the picture for us to look at.
The error message you are seeing is either a cable drop, or bad hardware, or hardware not recognised by the OS (drives not loaded etc). Is the card present in Network Neighbourhood? Can you change its configuration etc?
Try to attack the problem step by step in a logical manner and use a process of elimination.
Goodluck,
Yarrum
