Since there is no 'downgrade' option to Windows Vista, all that remains for you to do is to wipe all vestiges of Windows Vista from your new computer and install Windows XP. If you followed the instructions above, you hopefully now have the necessary drivers and software to complete a successful Windows XP installation. Back up all your personal data files before beginning.

Let's move into the installation with these steps as taken from PCSTATS Guide to Installing Windows XP.

Start the computer and insert your Windows XP CD. After a few seconds, the screen will clear and you will see a 'press any key to boot from CD' prompt.

If you do not get this prompt, and Windows Vista loads instead, you will need to set your computer up to boot from the CD/DVD drive first. To do this, restart the computer and press the 'DEL' key repeatedly (on laptops or some desktops, the correct key may instead be 'F2' or even the 'ESC' key). This will bring you into your computer's BIOS settings, which allow you to change some fundamental functions of the computer's hardware. You are looking for the 'boot order' setting, which depending on your computer will generally be in either the 'boot' menu or the 'advanced BIOS options' menu. Find this option and ensure that your CD device (which may be listed as either 'CD-ROM' or by the brand name of your drive, for example 'LG DVD-RAM HD55' etc.) is the first boot device. Hit 'F10' to save the changes and reboot your system.

Press any key to start the install. The prompt allowing you to install will time out after about 4 seconds, so if you don't hit any of the keyboard keys you will have to reboot to install.

The installer program will begin copying files from the CD. Once the 'welcome to setup' screen appears press enter to continue. View the licensing agreement and hit F8 to continue.

The installation program will then search your drives for any prior installation of Windows. If it finds one, you will be given the option to repair it, which essentially reinstalls most system files while leaving the registry and installed programs intact. Otherwise, move forward to the partitioning and formatting section of the install.

The initial screen shows the hard disks connected to your system, and any partitions that may already be created. You will see that the C: partition is listed as containing '(Vista)'. This is where your Vista installation resides, so we need to remove it. If you haven't backed up all your data by now, stop and do that, otherwise it will be erased. Highlight the C: hard drive partition and press 'D' to delete it. You will be prompted to confirm the action. Do so.

You now have a vista-free computer and a chunk of empty space where you can install Windows XP. Highlight the newly created 'unpartitioned space' and press ENTER to begin the XP install process. For more information on installing Windows XP, consult this guide on the subject, starting on page 3.

Now, connect to the Internet, start downloading software updates from Microsoft and relax. You are back on familiar ground again.