You might've heard the term "Virtual Machine" in some tech articles or what not. In case you don't know, a virtual machine is the emulation of an actual computer system. If emulation has negative connotations to your mind, don't worry, virtual machines are completely legal. In fact, the emulator DOSBox is actually considered to be more or less a virtual machine of a 486/Pentium PC.

In short, a virtual machine allows you to have two or more "computers" in your system. While it does tax your computer's resources, a modest virtual machine is actually a good way to increase your computer's functionality. For example, want to try out Linux but don't want to prep your hard drive for an install or multiboot? Creating a virtual machine allows you to skip all of that. So what exactly are the benefits in a nice list form?

• A clean machine to play around with, if you want to test drive an OS.
• "Multi-boot", and if you have the resources to spare, you can boot into many different OS's at once.
• Run your preferred OS in a limited sandbox mode. Curious about that one website but afraid it'll infect you computer? Let the virtual machine run it! If the virtual machine gets infected, it won't spread to your system.

Among other good things. But before we begin all of this, what do you need for a virtual machine?

Processor: If you have any of the following from Intel or AMD, you're good to go. If you don't, performance may suffer.

RAM: At least 2GB. Remember, the virtual machine uses as much actual RAM as you assign to it. So if you have a Virtual machine with 512MB, it will use up to that much of your real RAM.

Hard drive space: As much as possible. As with RAM, when you create a virtual machine, you also create a virtual hard drive which can take up as much space as you assign to it.

Graphics: Nothing special is required, but better performing cards may benefit more.

OS: The program I'll provide works with Windows XP and up, Mac OS X, and Linux. However, I'll only do the work for the Windows version, but it's very similar on the other OS's.

The virtual machine program we'll be using is Sun's VirtualBox ( http://www.virtualbox.org/wiki/Downloads ). This is probably one of the best free, fully featured virtual machine programs. While there is better (Parallels), they are also very expensive as most virtual machines were intended for the enterprise environment. However, VirtualBox does not support Mac OS X (and apparently no Windows or Linux based virtual machine program will), so if you were hoping to get that on a virtual machine, you're out of luck.

Download and install VirtualBox, once that's done, start it up and you'll get a window similar to this:



Click on the "New" button the top left corner. You'll be taken to a Wizard. Click on "Next" and then type the name of your virtual machine and the OS you intend to use (this is rather important).




Next set the amount of memory you want the virtual machine to have available. VirtualBox typically color codes the amount of RAM that is good before it starts to be a burden on your system.



Next is the virtual hard drive creation. You should create a new virtual hard drive even if this isn't your first virtual machine on Virtual Box. This will take you to another wizard.

Make sure "Dynamically expanding disk" is set, then sent the size. You may want to click on this folder icon to change where the drive will be stored. Virtual hard drives are real files on your actual hard drive, so you might want to keep the virtual hard drive somewhere easily accessible.



Confirm your settings and hit "Finish".



Before you start your machine, you'll have to configure it some more. Select your new virtual machine and press the "Settings" button at the top. The only thing you would really need to change here is the Display. If you have a lot of video card memory, set the memory size to 128MB. If you have a high end graphics card, enable 3D and 2D acceleration as well.

And in Storage, make sure you set the second IDE Controller slot to your DVD drive. Note that when you run your virtual machine, your actual OS can't use the DVD drive.



If you want to use a USB drive or other USB device with your virtual machine, this is how you can do it: Go to the USB settings, plug in your device, then click on the plug with the + to add the device.



Click on the picture for a larger image. Don't select devices like your keyboard, mouse, or network device (if you're using a wireless receiver). These will be automatically allocated to the virtual machine.

When you're done, start the virtual machine. Some things to note though:

• Installing the OS is exactly like installing the OS on your real machine. So if you've installed OS's before, this process should be familiar. If you haven't, well you can now learn how!
• If you click on the virtual machine's window, it will take over your keyboard and mouse. If you want to free these up, press the right CTRL button (this might be different on different OS's. There will be a pop up telling you how "unfocus" from the virtual machine)
• Any drives you've assigned to the virtual machine will be taken over until you've "shut down" the virtual machine.
• The virtual machine thinks it's hardwired to any network you're on, and it won't hog this resource (it uses a bridge connection). So if you have a wireless receiver on a network, that receiver will also work on the virtual machine, but your actual OS won't lose network service. Same with wired connection. Basically, if you have network access on your actual machine, your virtual machine will too.
• Sound is also included by default.

Now you may not like the second bit, where the virtual machine takes over your inputs. Wouldn't it be better if the virtual machine acted like any other Windows program? Well, VirtualBox has you covered! There's something called Guest Additions that you can install on your virtual machine that will provide the following:

• The virtual machine will behave like any other window. Normally your mouse, for example, will be confined within the virtual machine's borders. But with Guest Additions installed, you can move without that restriction.
• A "seamless" desktop mode where the desktop of the virtual machine OS integrates with your actual OS's desktop. If you were using Mac OSX for instance, you'll have your tool bar on top with a start menu on the bottom.
• Additional performance benefits. For example, more resolutions might be available to you.

However you can only install Guest Additions on Windows XP, Vista, 7, and Linux. The other versions of Windows will not work with Guest Additions. To install the Guest Additions, click on the virtual machine's window, select Devices -> CD/DVD Devices -> VBoxGuestAdditions.iso.



Then install them like you would any other program. For Windows, that would be to go to the CD drive and double click on it. For Linux, you'll need to do a sudo command.

You may also want to share your data between your virtual machine and your actual machine. To do so, click on Devices -> Shared Folders



Then click on the folder with the + on it. A new window will pop up. In this, type in the directory of the folder you want to share and the name of the folder you want it to show on your virtual machine. So if you share say CStuff and you label it Stuff, you'll find a folder called "Stuff" that leads to this directory.



If all goes well, open up Explorer (or whatever the equivalent is) and look for your shared folders. Windows Vista and 7 are similar to the image shown, but this is how you access the folder in XP (click on the image for a larger view).



There, enjoy your new machine within a machine! Now while VirtualBox does have 3D and 2D graphics acceleration support and an experimental DirectX support, you cannot use a virtual machine to play complex 3D games. 3D games with a software renderer will still work, but if you're hoping to get Windows XP performance on a Winodws 7 or Vista machine while playing Crysis, that's not what virtual machines are used for.

Also if you do have Windows 7 Professional or Ultimate, you may want to consider Windows XP Mode.

Feel free to drop any questions you may have for me.