This is a tricky one, and will probably be the category that most readers fall into, as almost every new computer from any big box or laptop manufacturer now ships with Windows Vista pre-installed.

How do you revert back to a Windows XP installation that never existed? Well, to be frank, you eliminate Windows Vista but save your data, if any exists, then chuck a new copy of XP onto the freshly de-loused system. It's not as simple as that of course...

If you are thinking of swapping Vista out for the familiar charms of Windows XP, the first thing you need to find out is if you have any software support available to make the switch. As you may or may not know, all versions of Windows require drivers, which are small pieces of software which tell Windows how to use the hardware in your computer correctly. These drivers are provided by your computer's manufacturer, or by the makers of the components inside your computer. Without the correct drivers, Windows XP will either refuse to install at all, or will install, but be only partially functional (no network connections, sound, etc.).

If you bought the computer from a 'big-box' retailer like Dell or E-Machines, or if it's a laptop, you will need to go to the manufacturer's website, look up the support section and cross your fingers that they have made Windows XP drivers available.

If the manufacturer has, download everything available and store it on a DVD or USB thumbdrive and read on. If they haven't made Windows XP drivers available, you may be out of luck in terms of loading XP right now. While it's possible to track down compatible drivers by identifying the various hardware in your computer and going straight to the source (the manufacturer's website), this can be unreasonably difficult as the computer's assembler has no obligation to provide you with this information. So while it's technically possible, that route is beyond the scope of this guide.

Tearing Down the Brick Wall of Windows Vista

The worst scenario you are likely to face is with a laptop computer that uses a serial ATA hard disk drive, as most new laptops do. Depending on the hardware used in your laptop, it is quite possible that no drivers exist or will ever exist to allow Windows XP to recognize the serial ATA drive controller in your laptop... Worse, if you do manage to get hold of compatible drivers for the SATA controller, installing them during the XP install process requires a floppy drive, something that's almost extinct in modern laptops. And no, a USB floppy drive will not work.

The ONLY way to install XP in this situation is to build a custom XP CD with the necessary drivers already added. PCSTATS can show you how in this Guide. Good luck (you'll need it, as well as a fair bit of patience). There is a ray of hope though. At least one manufacturer that we know of (ASUS) has released BIOS updates for several of their laptops that fix this previously insurmountable issue, so this is an avenue worth exploring. If not, look up your particular model of computer on Google. Chances are someone is in the same boat as you and may have an inkling of a solution.

Got a License for That?

The second essential bit of information you'll need before continuing is a valid Windows XP license for your computer. The Vista license key, will not work in Windows XP. This generally means that you will have to somehow locate a retail copy of Windows XP, unless you can convince the store that sold you the computer to also sell you an OEM copy of XP to go along with it.

As for using an old Windows XP license from a previous computer... well, Microsoft's End User License Agreement (EULA) ties XP licenses sold with a computer to that computer for life... "Windows... It's a life sentence". But we digress; the point is, you can't install Windows XP without a valid license. This PCSTATS cannot help you with.

If you have Vista Ultimate or Business though, you are in luck. Read 'the real reason to buy Vista Ultimate' below. Once you have the WinXP license and media sorted, read on.