If you'd prefer to resize your images or use a ruler with centimeters, millimeters, picas, or points, this is an easy change to make. Just go to the File tab in Word 2010 or the Office button in Word 2007 and choose Options. Now click Advanced and scroll until you see the Display section. Now select your choice next to Show measurements in units of:
If you aren't displaying the ruler and want to see your new units in action, you can turn it on from the View tab. If you want to resize an image using your new units, right click it and select Size and Position:
Excel has a similar option, but it only permits a switch to metric units.