Ever wanted to try out a new operating system (OS) but don't want to delete your current one?

A while ago we showed you how to partition your hard drive and install Windows 7 RC alongside your current version of Windows / other operating system, but if partitioning your hard drive seemed a tad daunting, there's another way that might seem simpler to you: virtualisation software.

With virtualisation software, you can install and run an operating system within a window in your current operating system. Think of it as running something like Ubuntu Linux as a "program" in Windows.

Of course, trying a new operating system out like this will require your computer to have a fair amount of horsepower.

There are a number of virtualisation programs available, but one free one that works quite nicely is VirtualBox. With it you can install other Windows installations and Linux operating systems.

Seeing as we've already discussed how to install Windows 7 RC, let's use that as an example of how to install another OS using VirtualBox:

1. Download and install VirtualBox.
2. Run VirtualBox.
3. You now have to create a virtual machine on your computer, so click on "New" (the big blue circle in the top left of VirtualBox).
4. A setup wizard now appears that will take you through the steps of setting up a virtual machine. Simply follow the instructions on screen carefully.
5. After the setup wizard has completed, you'll now see a new virtual machine in the list on the left in VirtualBox. Highlighting it will show you all the relevant information for this machine.
6. Highlight the new virtual machine by clicking on it once and then click on the "Start" button in VirtualBox (the green arrow).
7. As this is the first time you're "starting up" this virtual machine, there will be no operating system installed, so a "First Run Wizard" appears that will take you through the steps to install a new operating system.
8. Follow the instructions on screen, making sure you insert your Windows 7 RC installation CD in your DVD drive.
9. After the wizard has finished, a window will open and the Windows 7 RC installation will start as if you were running it on a real computer.
10. Install Windows 7 RC (have a look at this article to see how).
11. When you're done installing Windows 7 RC, you can switch the virtual machine off by clicking on "Machine" and then on "Close".

Once it's finished, you'll be able to run Windows 7 RC (or whichever operating system you installed this way) next time by simply opening VirtualBox and then starting the virtual machine again.

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