Context menus are those handy menus that pop up when you right click on Windows or control-click on a Mac. The content of these menus are specific to the area that is clicked and programs you install may modify the menu items that pop up in the context menu.
It is best to be a little patient and wait for your computer to completely finish booting before you start running programs.
Over time your Windows computer noticeably begins to take longer to startup and may suffer from degraded performance. Many times this is a result of entries that programs make instructing your computer to run them as soon as it starts up. This makes your computer take longer to become responsive once it is turned on. One solution for managing this startup clutter is a program called CCleaner.