I have a LAN NETWORK at home and it has been working fine for almost a year. But recently, I keep getting disconnected and when I do, all other computers get disconnected to. Only when I PLUG my cable out from the router, the other computers can reconnect. Whenever I try to reconnect, I am only able to stay online for about 3 seconds. After that, I wont be able to load a page even though it says I am still connected to the LAN. Does ANYONE know WHATS wrong? Whether it's my Ethernet card or a trojan or something? It's definitely not my ISP since I called them up.Can you give us a little more information about the host computer and the router?

Make/model of computer...operating system...malware protection being used...firewall being used...make/model of router?

Please be as specific as possible...Ask your ISP to replace the cable modem if it is theirs...they do eventually fail.Maybe you need to check if your windows is compromised. You need an operating system on a cd (knoppix, ubuntu): start the computer, boot from cd and see if the disconexion reappears. If so then your hardware is faulty (most probably your network card). Your router has a log option? Advanced? Can you see on the router management program (or webpage) what causes the blocking?
(I would advise you to use something else, but is POINTLESS if you didn't work with a packet sniffer before.)

My assumption is that your computer is virused.