How to Change Paper Size in Word 2007
Microsoft Word 2007 offers a variety of page setup options. You can customize many of the page features under the "Page Layout" menu. The different paper sizes include A4, Letter, Legal, Executive, A5, A5 Long Edge, A6, B5, B6, Com-10, DL, C5, Monarch, A4 Long, Folio, DL Long Edge, A3, JIS B4 and Ledger. You may also customize your page size by measurement if none of the options are suitable.
Open your Microsoft Word file.
Click on the "Page Layout" tab.
Click on the "Size" button in the "Page Setup" group.
Select the paper size you want. If you do not see the option you want, select "More Paper Sizes."
Click on the first drop-down menu under "Paper size" and scroll down to select "Custom size." Type in the height and width of the paper size by inches or use the up and down arrows to adjust. When you are finished, click "OK."