some of the networks when i'm trying to connect to with the windows vista i find that they are unidentified networks and so i can't log onto the internet through the network i'm two days trying to repair but i couldn't

Hi, Thank you for posting. Firstly, may I know if the connections are wireless or wired? At this time, please try the following to narrow down the issue: 1. Please go to the NIC (computer)s manufacture site and check if there is a new version of driver for the NIC released. If so, please remove the current version, reboot the computer and reinstall the new version to see how it works. If you want, you can also provide us the information about the NIC or the computer, such as brand, model, we will help you find the driver. 2. If there is no new version available, please just try removing the NIC driver, rebooting the computer and installing the driver again. 3. Please refer to the following Knowledge Base and try the methods and see if it helps: Windows Vista cannot obtain an IP address from certain routers or from certain non-Microsoft DHCP servers http://support.microsoft.com/kb/928233 4. If there are other computers on the network, please check if they meet this issue as well. If the issue persists, please run ipconfig /all in a elevated command prompt and post the result to this thread for our further research. Thanks.Nicholas Li - MSFT