Downgrade to Windows XP on Vista-preinstalled laptops

I've been receiving some very important requests from users running on Vista-powered laptops, asking me if there is any way to get rid of this system and install Windows XP instead.
If you are one of these people, demanding relatively fast, reliable and smooth-working Windows XP (of course it's not a perfect system anyway but it's still better alternative than, in my opinion, under-development, overloaded and slow Vista system), you should have known a few things before you try to kick out Vista from your computer:
1) First of all, if you have recently bought your laptop and it's covered by in-store warranty - this means you won't be able to get a replacement or cash return in case of accident, system crash, hardware failure or anything like that, bearing in mind that you have Windows XP installed already instead of Vista. So take it seriously that your laptop will not be covered anymore. If this is not a hardware issue you can simply put Vista back on track, booting laptop from System Recovery Disc provided. But you will probably lost all your data (not necessary if you have a backup). I don't think this situation affects your external warranty provided by manufacturer (if you have picked one). If you didn't take an in-store warranty, you are off the hook and you can do whatever you want.
2) Before you call for help and if you have some basic knowledge about systems installing process, give it a try: boot you laptop from CD with Windows XP and try to install the system, following the instructions on the blue screen (it works on older laptops). If SETUP can not recognize the hard drive that means you probably won't be able to put your hands on XP soon and your computer will require a professional help.

In my opinion, Windows Vista system is designed for computers having at least 4 GB RAM memory, with relatively fast processors and large hard drives. Otherwise it's really hard to get used to it. As Microsoft states: 2 GB is absolutely minimum - which means you will not be satisfied. Because who cares about minimum nowadays...?