Windows 8 Workstation no longer Uses Virtual PC // XP Mode. It comes with Hyper-V like Windows Server 8.
Hyper-V has no NAT Functionality included like VMWares Workstation, so we have to rely on OS features to do NAT to Use the Hosts Internet Connection when Connected to Hotspots or 3G Networks. Since RRAS is not available in Windows 8 Client, we can use Connection Sharing AKA ICS to connect to the Internet on a shared Connection ...
1. Have a look at your available Network Connections, give the Speaking names like Onboard LAN, WiFi or 3G like in this Example
2. Open Hyper-V Manager
3. Click on Virtual Switch Manager in Action Pane
4. Create a new Internal Switch
5. Give a Self Explaining Name for that switch. ( Here: Internal - Sharing )
6. Click Apply.
7. Go Back to your Network Connections in Control Panel.
Notice the Newly Created Network Connection, Internal - Sharing
8. Right Click on your Primary Internet Connection and select properties
9. Click on Sharing Tab
10. Tick the Allow other network Users ... and select your Internal Connection as Home Networking Connection
This will set your Internal Sharing to a Private IP Address and enables a DHCP on this adapter.
12. Back to Hyper-V Manager, give your VM Network Access through your Internal Connection
13. Start your Virtual Machine.
14. Go to your IP Configuration of the VM. Make sure that Dynamic IP is enabled.
15. Check your IP Address
Note that you have a dynamically assigned address with the Sharing IP ad Default gateway.The Doman is set to mshome.net
Connect to the Internet as you like.
You could easily switch between Internet Sharing Connections by Selecting Sharing on other Devices ... Configuration will remain for DHCP and Private Network....
If you want to have Fullscreen Support for your Virtual Machines: Even on Windows 8 Client the same as for Server applies: The Hyper-V Console Connection is Limited to 1600x1200 and does not have Notebook Specific Resolutuions like 1440x900.
Microsoft recommends using RDP Connections for that. Just use Remote Desktop and connct to [youvitualpc].mshome.net and your RDP Session will also work when doing VPN like anyconnect from within your machine :-)