1 Virtual Machines & How to set one up with Virtualbox

Virtual Machines are guest operating systems which are installed in a host operating system. Think of it as a secondary operating system in your computer, and you can run it at the same time with your operating system. The biggest function of virtual machines is the fact that they're isolated from the host (primary OS), which means they are in no means related.

The reason why everyone uses virtual machines is simply because you can have different operating systems on your computer without changing your preferred operating system. This comes handy for people who have programs which aren't compatible with Windows 7, people who need to use Linux for programming, people who want to test software/settings without altering their original operating system and many more things that I can't think of right now.

The only disadvantage of using virtual machines is that it runs slower compared to a host operating system. Since it accesses the hardware indirectly, the performance will be poorer compared to the main system. It might also end up slowing down your host operating system if you don't have enough resources to run them.

Setting virtual machines up are fairly easy. First things first, let's list the things you need to set your own virtual machine.

- VirtualBox for Windows (Note that there are alternatives to VirtualBox, but in all honesty, it's the easiest one to use and it covers everything you need.)
- ISO file of the Operating System you wish to use (Backtrack 5 in my example)

That's pretty much all we need! Start with downloading and installing VirtualBox. After that, we'll see the main window of VirtualBox. To create our Virtual Machine, we simply click the "New" button, give it a name, and select its version.

When we are done with that, the software will ask how much memory we want to allocate to our Virtual Machine. (this can be changed later, so don't worry about misconfiguring it) I have 6 gigabytes of RAM installed in my computer, so I will just give 2 gigabytes of RAM to it. This is totally optional and you should configure it according to your needs.

The next step is making a "hard disk". Select the Create new hard disk option, and check the Start-up Disk option to proceed. Leave the file type at default. (VDI - VirtualBox Disk Image)

It's going to ask you if you want to have a fixed or dynamic hard drive. Dynamically allocated is usually a better choice since it will save you from using unneeded space on your hard drive. I'll select dynamically allocated for this example. After that's done, we are supposed to allocate a starting space for our hard drive (it ll expand after you fill this space up, that's how dynamic works)

Now, we have an empty Virtual Machine in our hands. It's time to load our Operating System in it! But first things first, click Settings in the main window, and assign more Video Memory and Cores to it, so it runs optimally. (You can do this by going to System-> Processor / Display -> Video)

To install the OS, we need to import the ISO file we wish to use into Virtualbox. This can by starting the VM up, going to Devices -> CD/DVD -> IDE/SATA (doesn't really matter) -> Choose a Virtual CD/DVD file. After the DVD is loaded, you will see the installation screen of your Operating System. (In a Windows 7 example, you will see the screen as if you re installing a fresh Windows 7 copy on your computer.)

After the installing part is done, your virtual machine will restart, and you will be seeing a fresh installed operating system of your choice! You might want to install Guest Additions as it's needed to fix some driver issues. (This can be done in the Devices menu again) Congratulations! You just successfully created your own virtual machine.

Now you can tweak it the way you want to and make use of it. You can also share things like your folders, your network, or your clipboard between your host and guest system, which makes it quite versatile to use.

I hope you liked this tutorial! I'm glad if I could have been any help :)