Entire new computer, 60g HD, XP, all bells and whistles, less than $500. WHY would you want to go back to a system that doesn't work, never did work well, and is incompatable with todays software. All you would do is destroy the capabilities of the computer.
I was not the one wanting to go back. I was just projecting myself into the future. XP will be obsolete and unsupported one day and we'll be faced with the same decision the OP is facing now, that was my point.