Welcome to Microsoft's Windows XP Professional Windows Parallel Install step by step. This will give you an idea on how to do this when and if the time arises for you to parallel install your operating system from Windows. This install guide is fully graphical and will take you through each step of the installation.
What you will require to do this walkthrough is
A Windows XP Professional CD
A Computer with CD-ROM access and previous operating system.
To start this Windows install insert the CD from the desktop. The CD will autorun, else go to My Computer, the CD-ROM drive and double click on the "SETUP.EXE" file. The install will begin.
Remember to backup all important information before performing this task.
