If you would like to use multiple operating systems on your machine then we know we can install in separate drive or same drive or better to say partitioning hard disk. But there is another way to do the job without messing up your hard disk partition. No need to worry about, it is so simple to install/uninstall more than one operating systems on your PC or laptop on the fly!

You need a software named VirtualBox, you will be happy to know that it is an open source software developed by Sun.

Presently, VirtualBox runs on Windows, Linux, Macintosh and OpenSolaris hosts and supports a large number of guest operating systems including but not limited to Windows (NT 4.0, 2000, XP, Server 2003, Vista, Windows 7), DOS/Windows 3.x, Linux (2.4 and 2.6), Solaris and OpenSolaris, and OpenBSD.

That means you can install this software on Windows, Linux, Mac and OpenSolaris and install other operating systems by this software, you may have Linux, now install this VirtualBox and you would be able to install Windows 7 easily without messing up your harddisk or partitioning or spending time to install OS. No need USB drive also to test OS like Ubuntu or SuseLinux etc, you may install Windows 7 also. Those who are interested to install Windows 7 on external hard disk they may try using this software. Windows OS generally can not be installed on external hard disk, though by changing some files XP can be installed on external hard disk or USB disk (tested). Although we may not install Windows 7 on external hard disk.

You have to create Virtual hard disk to install Guest OS, but this is also an easier task, follow all steps correctly using Wizards. You may also remove the Virtual hard disk easily :)

Take a look I am installing more than one operating systems Ubuntu and Debian O/S simultaneously, my machine runs on Windows Vista

From the screen shot hope you understand how you could save time and test as many OS as you would like to run.

Only thing which I did not like is the window size is 800×600, guest OS could not detect my monitor and Display size is smaller, running on 24Bit than 32Bit color quality.

So, install many operating systems and see what may be a good choice for you!

After Installing Ubuntu and Debian: