The simple answer is you probably shouldn't be bothering with configuring computers to Multiboot any more. Multibooting is a
technique that is used to run two or more operating systems on a single host computer. Some people use this method to set up a
multiboot computer to run more than one operating system such as Windows XP and Windows Server 2003, or Windows XP and Linux
Red Hat. However, multibooting can be problematical and, if it is not done properly, can leave your system inoperable.
A painless way to enjoy the benefits of multibooting without the difficulties is to use a virtualization application that
runs on a host computer. Today, there are many options available and most of them are free for use. An example of a virtualization
application that Microsoft offers is called Virtual PC 2007. It's a free download you can use to install multiple operating systems
on your computer, and then switch between them as easily as you switch between programs. You can download Virtual PC 2007 directly
from the Microsoft Virtual PC 2007 website.
The main drawback for a Multiboot system is that it requires separate partitions on your computer's hard disk for each operating system. You also need to install the oldest operating system first, which can be frustrating if you want to add an earlier operating system after you have already begun the process. In other words if you install Windows Vista first, it will be very difficult to install Windows XP after the fact. Installing an earlier version of Windows after a more recent version is already installed can and most likely will render your computer inoperable. This can happen because earlier versions of Windows do not recognize the startup files used in more recent versions of Windows and can overwrite them.
Virtualization programs allow you to create virtual computers (called virtual machines, or guest computers) on your computer (also known as the host computer). The virtual machine shares system resources such as random access memory (RAM), hard disk space, and the central processing unit (CPU) with the host computer. The major advantage to you is the ability to install operating systems in any order and without disk partitioning. You can minimize or expand the virtual PC window just like a program or folder, and switch between it and other windows on your desktop. In addition, unlike multibooting where you can only run one operating system at a time, you can have multiple guest running assuming that you have enough resources available to share. You can install programs on the virtual machine, save files to it, and pause the virtual machine so that it stops using computer resources on the host computer.
If you are interested in learning more about virtualization, I would recommend that you look into the following products. I find Microsoft’s version very easy to install and use. However, the Microsoft version may not support all of the guests that you may be interested in running. In addition, Virtual PC 2007 does not support 64-bit guests (as of this writing).
Microsoft Virtual PC
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