eXtra Buttons is a free program for Windows that allows you to add to the list of built-in buttons in your windows, thereby increasing the number of functions they can perform.
You can change the transparency of the window, permanently bring it to the top, send it to the system tray, or create a copy of the window.
You can customize the buttons you want to appear in your windows and disable those you do not want to use. You can also edit the order of the buttons and add separators.
Each of the functions associated with a button can be modified in the program options. From the options window, you can also exclude programs and modify the window menu.
eXtra Buttons is definitely highly recommended for those of you who want to make the most of your Windows desktop.