Downgrading from Vista back to XP Pro

I have a Centrino laptop (1Gb) which I upgraded to Vista Business. It ran
real slow – especially when I added Office 2007. I bought a 2Gb flash
disk to use power boost – but the system is still slow.
I want to go back to XP Pro and Office 2003. Can this be done?
I will ensure all my documents are in compatible mode before doing
this.
Any comments on this reversal?
Regards