Cropping in PCS2

I checked the memories but could not find what I was looking for. I just upgraded to Photoshop CS2. When I used Photoshop 7, I would crop my pictures by choosing the crop tool, making the W&H 100x100 and then just crop. Well, for some reason, that isn't working in CS2. I don't know if I am forgetting to click something or what but it just will not crop down to 100x100. Is there a tutorial on cropping for CS2 anywhere? Can anyone help? Thanks!