>When you right click on the Start button there is a little menu that appears. Sometimes when you install software there is new entry in that menu, how can we add or delete some of those entries.

From windows help. :-)

"To add a program to the Start or Programs menu

1 Click the Start button, and then point to Settings.

2 Click Taskbar, and then click the Start Menu Programs tab.
3 Click Add, and then click Browse.
4 Locate the program you want to add, and then double-click it.
5 Click Next, and then double-click the menu on which you want the program to appear.
6 Type the name that you want to see on the menu, and then click Finish.
If Windows prompts you to choose an icon, click one, and then click Finish.

Tip

You can also add a program to the top of the Start menu by dragging the program's icon onto the Start button."