If you are talking about your office/typing software replacing the text you've typed instead of inserting new text at the location, then you may have accidentally pressed the 'insert' key on your keyboard. Pressing 'insert' again will turn this behavior on and off.
The Easy Button can be purchased at Staples stores or on their online store. They also have a desktop application to have an Easy Button on your computer.
where is the navigation button on my computer
sizing button
the power button
This would depend on the type and model of computer. Generally, on a desktop computer, the power button will be on the front of the tower. Sometimes it can be on the side of the tower if not on the front. If it is an all-in-one computer, such as the imac, it may be on the monitor itself (possibly back or front). If you are using a laptop, it can often be found at the top right just above the keyboard. some older laptops have the button on either the side or front of the laptop.
Start button/Windows button/Windows Key and then click where it says (My)Computer
No such button.
By pressing the C button then the L button then the E button and last but not least the F button on your computer ( make sure you do it in a word document).
There are several possibilities but I'd start with the power supply. Test it before you replace it.
start button
close button
Which one? The one to the main SPY computer is the big red button on the control panel of the computer.