To solve this problem, I combined steps from this 2 posts:
Windows Phone 8 emulator error - Something happened while creating a switch
and
http://mobileworld.appamundi.com/blogs/petevickers/archive/2012/11/01/troubleshooting-windows-phone-8-emulator-problems.aspx.
I first ran XdeCleanup.exe from C:\Program Files (x86)\Microsoft XDE\8.0.
Then, I entered Hyper-V Manager and created a new Virtual Switch (as described in the articles) - in Control Panel\Network and Internet\Network Connections it was created under the name vEthernet (Windows Phone Emulator Internal Switch).
I was also facing the problem that my internet connection uses user configured IP settings.
The emulator created another virtual switch, called vEthernet (Broadcom NetLink (TM) Gigabit Ethernet Virtual Switch) , which resulted in no internet connection for my computer (Broadcom NetLink (TM) Gigabit Ethernet is the name of my real network adapter to which the created virtual switch was connected).
So, what I did was set the IP address and the other information of the virtual switch vEthernet (Broadcom NetLink (TM) Gigabit Ethernet Virtual Switch) to the information for the real adapter, which solved the internet connection problem of my PC.
Hope this helps