Hi,
The problem you describe is probably not your keyboard. It will be related to your touchpad. When typing on you laptop keyboard you are brushing the touchpad with your hand and moving the pointer to a different location on screen. When you continue to type the text appears where the pointer/cursor has moved to.
Try reducing the sensitivity of your touchpad, by using the application. Im guessing its a synaptics touchpad. If the laptop is using the default windows driver, this makes the touchpad too sensitive. You will have to download the appropriate software driver for it.
Regards,
Chris.