My Samsung ML-2955ND Network printer, prints good in WORD but prints on a half page in landscape in Excel so the printer is ok I guess so does anyone know how to fix this?

Obvious things first: have you checked the formatting of the Excel spreadsheet(s) you've printed? Could there be embedded page breaks, or even unusually large top/bottom margins?

Check your Printer Properties and see if you have options to center vertically, center horizontally, etc. If so, play with those options until you can see a print preview that looks correct. Then after printing, save with that configuration.
HTH,
Gary