It depends on what version of Word do you have. In newer versions, it is a bit confusing. In versions 1997-2003 you go to FILE and then OPEN. In new 2007 and 2010 you go to circle logo at left upper corner, pres it and then OPEN.
Open new MS Word document, then go to office button and open it.Go to open dialog box and click it using left mouse button and also by using Ctrl+O u can open a Open Dialog box.Now u can browse the required document and open it.