As I type, the cursor will move back to the very first word type with same letters.

As I type, the cursor will move back and forth to the very first words typed with same letters or double letters. I assume it is a formatting problem.

Sounds like a possible driver issue. If this is a serial keyboard (very old) then you need to change it to "no echo". What type of connection do you have?
PS2, usb, serial?