i wouldn't declare that statement to be totally true in all cases.
all can be taken back to xp, but the computers/laptops especially loaded with proprietary hardware, designed for vista, will not have xp driver support.
i took a new compaq in on a trade for an xp dell, [customer didn't like vista].
it would run xp, but without any support for video, sound , harddrive etc. support.
this compaq was assembled just for vista
The article mentions the need for XP drivers. I have requested all the necessary XP drivers from Acer, and will not attempt the downgrade until I have them. I will report here if I receive the drivers, and again if they work...LOL
When purchasing an Acer desktop back in August, the first thing I did was partition the drive and add Windows XP Home Edition. Gettting it set up was admittedly a pain, but after many hours of trial, error, and frustration (I was actually happy one afternoon when a thunderstorm came up, forcing a badly needed break), I did end up with a system that can be booted into either Vista or XP. Searching newsgroups helped immensely, particularly in helping to find some "mystery" drivers that simply showed up as question marks with very little hint as to what they were.
I also ended up transplanting a floppy drive from my old system to the Acer, as SATA drivers were demanded by Windows XP during the install process...and floppy seemed to be the only way to load them in at the time.