keyboard keeps acting up.......

im on my lap top now,and i have to use an external key board to type,becuas the guy who owned the lap top befor me spilled some coffie on it and the key board quit.but the external key board is pluged in to the usb and after u start the lap top u have to mash a mess load of buttons for like20min to an hr befor you get it to wrk.ive checked the usbs and they are all fine,dose any one know what i can do or dose any one have any suggestions??????????????

 

remove and clean the original keyboard, this may solve the issue, otherwise you may need to change some settings, I'm not sure which ones.