Fixing the “Unable to initialize Virtual Switch Networking” error message

I was introduced to Mac OS X by my friend CW two years ago, and purchased my first Mac (G4 powerbook ) a few months later. After switching to OS X, I started to miss the ability to run Microsoft Windows applications. I decided to purchase a copy of Virtual PC 7.0 to run the Windows applications (VPN Client, Access, etc.) I couldn’t run natively under OS X, and things worked great until I purchased OS X Tiger. When I attempted to run Virtual PC under Tiger, I was greeted with the following error message:

Unable to initialize Virtual Switch Networking

I started digging through various forums as well as the Microsoft website, and soon learned that this was a known incompatibility between Virtual PC and OS X Tiger. Since the virtual switch functionality no longer worked, I decided to take “shared networking” for a spin. If you are unfamiliar with shared networking, it is NAT functionality built into Virtual PC, which allows the guest PC to share the host Operating System’s IP address. When I enabled shared networking and enabled DHCP on my Windows 2000 host, the box was able to DHCP an address, but the networking support was unreliable. For some reason the DNS servers and default routes would get set incorrectly, which of course caused my network connectivity to quit working. Upon doing a bit of investigation, I realized that Virtual PC assigned IP addresses in the 192.168.0/24 network. Since DHCP wasn’t working correctly, I decided to hard code my IP address (192.168.131.66), DNS server (192.168.131.254), and default router (192.168.131.254):

C:\>ipconfig /all

Windows 2000 IP Configuration

      Host Name . . . . . . . . . . . . : cupojoe
      Primary DNS Suffix  . . . . . . . :
      Node Type . . . . . . . . . . . . : Hybrid
      IP Routing Enabled. . . . . . . . : N        
      WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

      Connection-specific DNS Suffix  . :
      Description . . . . . . . . . . . : Intel 21041 Based PCI Ethernet Adapter
      Physical Address. . . . . . . . . : 00-03-FF-2B-72-C8
      DHCP Enabled. . . . . . . . . . . : No
      IP Address. . . . . . . . . . . . : 192.168.131.66
      Subnet Mask . . . . . . . . . . . : 255.255.255.0
      Default Gateway . . . . . . . . . : 192.168.131.25
      DNS Servers . . . . . . . . . . . : 192.168.131.254
      Primary WINS Server . . . . . . . : 192.168.1.2

This did the trick, and things have been super stable since. Jeah!