How to get back Applications menu?
In top left in file menu there suppose to be application but it's not there,everytime i have use dash to use my installed programs.
Unity doesn't have an "Application" menu in the top left, and the menu you're seeing is for the desktop. It should say "Ubuntu Desktop" when you're not hovering over that bar. Application menus in Unity are merged in with the panel, and it will always show the currently focused application.
If you're wanting the "Application" menu, you would need to use GNOME2. You can use GNOME2 by selecting it on your login page. It should be listed as "GNOME (Classic)".
If it's not located in the above box, run
If you want to stick with GNOME3, you can take a try at Cinnamon. You can install Cinnamon with: