Try the Troubleshooting the Windows Phone 8 Emulator: http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj681694(v=vs.105).aspx
You will find the following topics:
- Cannot connect to Internet destinations
- Cannot connect to a local web service on the development computer
- Cannot connect to network destinations on a domain or corporate network
- Cannot connect to network destinations when network settings require manual configuration
- Emulator starts slowly or fails to start and app deployment fails
- Interference from other virtualization or networking software and drivers
- Computer fails to boot after installing the Windows Phone SDK 8.0


