回複：Please help: 電腦一接 LAN， 其他運行程序的啟動就慢下來.

It sounds like you are infected by the either virus or spyware. On command promp, type "netstat", you should see all the connection from your computer to other site or machines. if you find any connection should not be there, you are hit by the virus or spyware. if this is the case, check my post at http://web.wenxuecity.com/BBSView.php?SubID=computer_best&MsgID=360

get your antivirus and anti-spyware installed.

good luck