A virtual machine is a software, that lets you create and run a separate operating system in your existing computer system. You can boot the virtual machine from the parent operating system and run just like another software application.
For example: If you are using Windows xp, you can install popular virtualization software like Windows virtual PC, Vmware workstation to create a virtual machine within your current operating system. Now in that virtual machine, you can install any operating system e.g Windows xp, vista. You can run these operating systems in a new explorer window within Windows xp.
The problem with virtual machines is that you have to install an operating system from scratch. This includes loading the operating system from cd or dvd, installing all the drivers and system software etc. This can be very time consuming and is not a quick job.
How to Convert your Existing Operating System into a Virtual Machine
Microsoft has a free application named Disk2vhd, which can create a virtual machine of your existing operating system. The utility is a portable application and does not require any installation. You can run the virtual machine on any computer you want.
Following are the steps involved to create the virtual machine of your existing Windows operating system:
1. Download the Zip file (751 Kb) and extract it. After that, just run the Disktovhd. exe.
2. The application will show you the available drives in your computer.
3. Select the drive which you want to migrate as a virtual machine. In this case, i would want to create a virtual machine for my Vista installation, hence i have selected the D drive.
4. Specify the path where you want to save the virtual hard drive (vhd) file. The file would be of large size and almost equal to the size of the operating system drive.
5. Hit the Create button. It would take some time to create the vhd file (mine took 25 minutes).
The software will clone a virtual hard disk of the drive selected and save it in specified location. After the vhd file has been created, you can use any virtualization software to mount the virtual hard disk and run the operating system as a virtual machine.
For example: I mounted the virtual hard disk on Microsoft Virtual PC and ran Windows Vista as a virtual machine under Windows xp. The software can convert the chosen hard drive into a vhd file, even if it is under use.
How can the Virtual machine be useful
Using a virtual machine has many advantages, especially when you are tech savy. Consider you are working in Windows xp and need to test a small Windows application compatible with Windows vista only. In that case you have to boot your system and start Windows vista again. A virtual hard disk of vista will come in handy here as you can start testing the vista compatible application by starting a virtual machine in xp.
Another situation where virtual machine can be a real time saver is when you are using multiple computers. Suppose you want to work in your friends computer with all your installed software and applications. In that case, just create a virtual hard drive of your operating system and carry the vhd file in a usb stick. When you are using the friend’s computer, just mount the virtual hard disk and use all your installed software.
Disktovhd can be used to create virtual hard drives of Windows xp, Windows vista, Windows server 2003. If you are using Ubuntu, check out how to create an Ubuntu virtual machine.