Microsoft has released a new tool to do this for you or you can manually reset TCP/IP.
Microsoft Fix it
The tool “Microsoft Fix it” should help reset TCP/IP in Windows 7. Click here to download from microsoft website.
Reset TCP/IP manually
To reset TCP/IP manually, run the following:
1.Click Start – type “cmd” in Search. Right-click “cmd” and select “Run as administrator”
2. From the command prompt,
netsh int ip reset logfile.txt
This should reset TCP/IP and log the changes to the log file (logfile.txt) in the current directory from where it was run. You may specifiy an absolute path like c:\logfile.txt.
3. Restart the computer for the changes to take effect.