Open the Settings Manager from the applications menu and click the Appearance icon. Select Win2-7-theme in the Style list and select Win2-7 in the Icons list.
Press Alt+F2 and run the following command to get Windows 7-style window borders. If you're typing this out rather than copying and pasting, note that the command includes a double-dash, not a long em dash.
Go into the Session and Startup panel in the Settings Manager, select the Application Autostarttab, and click the Add button. Enter Metacity as the application's name and metacity --replace as its command. Now Windows 7-style window borders will automatically start with your desktop.
To make your panel look more like Windows 7's panel, right-click it, point to Panel, and select Panel Preferences. On the Appearance tab, select Background image and browse to the \usr\share\themes\Win2-7-theme\gtk-2.0\Panel\ directory on your computer. Select a background image like Panel_Win2-7Basic800.png. The theme pack we installed includes a variety of panel backgrounds, so feel free to experiment.
You can also change the applications menu's graphic and make it use a Windows 7-style start orb. First, find a Windows 7 start orb image--you can find several on Google Images, but make sure you get a transparent PNG image. Once you've found a good image, right-click the Applications menu button, select Properties, and use the Icon button to select your start orb.
Phew, that took a lot of tweaking (and a lot of text)--but we now have a Windows 7-style desktop on Ubuntu. It lacks a Windows 7-style Start menu and taskbar, but Windows users that prefer the classic Start menu and taskbar behavior will find it immediately familiar.
Undoing your changes
Want to undo your changes? If you followed the first method, just run these commands. Remember to log out and log back in after running the commands to restore the global menu bar.
gsettings reset org.gnome.desktop.interface gtk-theme
gsettings reset org.gnome.desktop.wm.preferences theme
gsettings reset org.gnome.desktop.interface icon-theme
gsettings reset org.gnome.desktop.wm.preferences button-layout
gsettings reset org.gnome.desktop.background picture-uri
sudo apt-get install appmenu-gtk appmenu-gtk3 appmenu-qt indicator-appmenu
If you followed the second method, log out and select Ubuntu's default desktop environment from the login screen. You can toggle between the two whenever you like. If you'd like to uninstall Xfce, use this command:
sudo apt-get autoremove xubuntu-desktop