Scenario 2: Host Linux Under Windows, Using VirtualBox
Sun Microsystems should rename its free, open-source virtualization utility VersatileBox. Not only does it run on Windows, Linux, Mac, and Sun's OpenSolaris, but it also supports an even wider array of guest OSs, including just about any version of Windows.
Let's say you want to start learning to use some Linux tools and applications without dual-booting or repartitioning. Download the Windows version of VirtualBox from Sun's site, and install it. Launch it and click on New to create a new virtual machine.
Click on Next to start the installation process, enter a name for your virtual machine in the dialog box that follows, select an operating system type from the OS Type list, and click Next. Click Next again to accept the default base memory size for your virtual machine (or adjust the slider up or down), and then click Next. Because Linux runs well with minimal system resources, you really needn't allot more than 128MB of RAM to the virtual machine in most cases.
Click New to create and size a virtual hard-disk file; I recommend choosing the dynamically sized option, which will allow the virtual hard-drive size to expand as you fill it with data. Click Finish to create the virtual disk, and then select Next and Finish to complete the virtual-machine creation process.
Now, select your new virtual machine in the Sun xVM VirtualBox console, insert the Linux boot media, and click on Start to begin the boot and installation process. Once everything is installed, launch the virtual OS by selecting it in the Sun xVM VirtualBox window and clicking Start.
Like Virtual PC 2007, VirtualBox runs your guest OS in a window, and grabs the mouse pointer automatically once you click inside it. To release the pointer to the host OS, press the right-hand Ctrl key. To enter full-screen mode, choose Machine, Fullscreen Mode, or press the right-hand Ctrl key and the F key at the same time. To escape full-screen mode, press that key combo again.