I am trying execute desktop programs using Xvfb but the titlebar are missing.
Example:
# start desktop environment
Xvfb :1 -screen 0 1024x768x16 &
# access to desktop environment
x11vnc -display :1 -localhost &
vncviewer :0 &
# run wine
DISPLAY=:1 wine winecfg
Titlebars on windows are the responsibility of the window manager. Since you didn't run one, you're getting only the interface elements actually provided by the application.
I don't know what the fashionable window manager is these days... if you're very traditional, this will work: