I’ve heard a bit of confusion recently over just what is needed to create 64-bit virtual machines using Microsoft technologies. Part of the confusion stems from the very liberal use of the term “64-bit support” by much of the Microsoft marketing folks in relation to their virtualization offerings. So lets clear things up.
First, here’s the list of Microsoft operating system virtualization products:
- Virtual PC 2007
- Virtual Server 2005 R2
- Hyper-V for Windows Server 2008
- Hyper-V R2 for Windows Server 2008 R2
Next, lets get some terms straight:
- Host: This is the physical server that is running the operating system virtualization software.
- Guest: This is the virtual machine running within the operating system virtualization software on the host.
The confusion I mentioned earlier comes from the Microsoft marketing folks use of the term “64-bit support”. So what does “64-bit support” mean?
According to Microsoft marketing:
The operating system virtualization software that can be installed on a 64-bit host.
According to everyone else:
The virtualization software can be used to create 64-bit guests.
Now that we have our terms in order, we will answer the real question: what Microsoft products can be used to create 64-bit guests? The answer: Hyper-V and Hyper-V R2. That’s it. Virtual PC and Virtual Server can only create 32-bit guests, even when installed on 64-bit hosts. What does this mean for you?
If you want to create 64-bit virtual machines using Microsoft products, you need:
- Windows Server 2008 x64, Standard or Enterprise or Windows Server 2008 R2 x64, Standard or Enterprise running on a 64-bit host computer
- Hyper-V or Hyper-V R2
- The host computer CPU(s) must have the VT extensions turned on. These are turned off by default on many desktop and workstation class machines.
It also means that you can not run 64-bit guest virtual machines using Microsoft virtualization software on Windows XP, Vista, Windows 7, or Windows Server 2003 host operating systems, even if using the 64-bit versions of these operating systems. If you want to run 64-bit guests on any of these operating systems, you will need to look at virtualization software from another vendor, such as VMware, which also has a number of free virtualization offerings: VMware Server and VMware ESXi.