I'm currently running XP with standard Pentium 3 @600 Mhz and 128 Megs or RAM (waiting for 256 Mb). It works perfectly, only few glitches when I have 3+ applications open at same time (but this is just due to RAM, and will be fixed VERY soon!).
Windows 2000 runs a bit more slowly - even if I thought the exact opposite. By the way, using this CD i could try the two configurations (2000 vs XP) in few minutes.

The whole procedure consist in 'burning' the working "image" of the OS onto your hard drive. This will of course cause the lost of all your data so remember to do a backup first.
Then ,the new system, along with drivers and softwares is copied onto the hard disk.
After that, you can mount the hard disk again into the Stylistic, and voilà! Everything works like a charm!
There's also a tool useful to change license number of OS to your very own so it will become licensed after installation (BTW its not strictly necessary for everything to work, such as updates and other stuff).
Only problem to me was that OS is in Italian, and you have to download language pack after installation to convert system to English (it took me half an hour, from beginning of download to ending of installation).