(Rephrased version) Dear all, Just as what you guys feel, I've keep searching for a solution of this problem. Some people think that it is a bug, but I proved, it's not ture. Motivated by my curiosity and hacker sprits, I figured out that the problem is caused by a failed IPv6 stack problem, which repeatly shown in my event log. To address this problem, I tried to disable IPv6, disable new dynamic stack, disable firewalls, enable static IP and so on. But they all failed. To my surprise, the solution is extremely simple. 1. Disable the satic IP and ICS (if you have set previously). 2. Go to Control panel > Network and Internet > Network and Sharing center > Managing network connections (on the right corner)> Select all connections > right click on one of the connections > click "Network bridging" 3. When finished, right click on the icon of Network Bridge > select "properties" > go through the UAC by clicking "contiune">remove the tick of your Internet connection in the upper box > click "OK" 4. Right click the icon of your Internet connection > select "properties" > go through the UAC by clicking "contiune"> go to the "sharing" page, tick both check box. > click "OK" Now, wait for the Windows Vista to recongnize the new network setting. Wait a minute and check if both computers can get access to the Interent. If the tricks failed to work, just restart both of PC. Lastly, I would like to say sorry to all of you as I am not a native in English. There may be many grammar and spelling mistakes. Please correct me.