A family of Microsoft word processing software products for creating web, email, and print documents.
In the Print dialog, under Zoom: Pages per sheet, choose "2 pages." This will reduce your A4 page to A5 size and print two pages side-by-side on a landscape A4 sheet.
You must do this every time you print; in future, you might want to use the "2 pages per sheet" option under "Multiple pages" on the Margins tab of Page Setup, which allows you to create A5 pages to begin with; they will also print two-up on a landscape A4 sheet.
Note that if you want to print a single page twice on a sheet, you must enter the page number twice in the "Pages" box (for example,"1,1" ).
For a complete explanation of all the "2 pages per sheet" options, see http://wordfaqs.mvps.org/2PagesPerSheet.htm.