Word 2007 blank page displaying square boxes

Hello,
Please can anyone help me. I was typing in english and then I wanted to change to chinese. I pressed shift and alt and immediately struck g to start to type in hanzi (chinesecharacters) that is when square boxes emerged to the background of what I was typing. I tried to open a blank new page but the blank page is no longer blank since it's displaying boxes. even my previous documents are displaying theses boxes in the background. if I change the background colours they still remain. please help me to get over this problem. I used this shift and alt before with no problems. please help