Mouse doesn't work in Microsoft Word to select text, or highlight text to copy or add features such as bold/italics/underline.

After pasting an E-mail into a Microsoft Word document (which I do all the time), my mouse stopped working to click anywhere in the document and it won't allow me to use the side scroll bar.  I can still click on tabs and commands up top and the page up and down buttons, but I can't highlight text to underline/bold/italics or to copy or move around in the document.  I use these features all the time and am very frustrated.  I can still do all of these things in other applications such as E-mail, Facebook, Internet but not in Word.  Please help.  I have already checked my mouse settings and drivers and they are all up-to-date without errors.  I have restarted my computer; the only next step I can think of is reinstalling Microsoft Office Professional 2007.  I appreciate any assistance you can provide.  Respectfully, Julie