1. Get Ubuntu
If you are not already using it, download Ubuntu from ubuntu.com.
2. Vista fonts
You need the microsoft segoe UI font.
Look at the second post in this Forum
Unzip the downloaded archive and place the two .ttf files in your .fonts directory.
You can find it in your user folder. /home/$USERNAME/.fonts/
For example: /home/kimmik/.fonts
If the directory .fonts does not exist, create it.
3. The Aero-clone theme
Download the Aero-clone theme from Gnome-look.org
Install the Beryl and GTK theme as usual
Download the nuoveXT-aero iconset
Install the nuoveXT-aero iconset
Change the gnome-panel size to 32px height
6. Vista start-button screenlet
Download and install “Desktop Screenlets”
Install the “orb” screenlet (The orb screenlet is included in the .tar.gz from gnome-look.org).
Place the orb screenlet above the main-menu button and lock the position.
If you want to make the experience complete download some Vista wallpapers for your desktop.
I found very good wallpapers on this forum: