Netsh is a valuable command-line tool available from Windows 2000 onwards. I recently had a client who was unable to get his wireless adapter to repair, no matter how many times he rebooted, repaired, disabled, etc. It would associate with the access point but never pull a correct IP. Instead, it kept going to some non-self assigned IP (202.61.xx.xx) All it took were the following commands (he didn't have any special settings, so when in doubt, reset everything you can!)
netsh interface reset all
netsh winsock reset
A quick reboot later, and the wireless jumped right on and got a valid IP from the DHCP server.
Additional Netsh Resources
- Microsoft's KB article - basic usage and description of the various contexts
- Petri has more advanced uses for the tool.
- Microsoft Technet Command Line Reference - Using Netsh