Here's how to remove Office 2013 in order to install a new version without having to reinstall Windows.
QUESTION My installation of Microsoft Office 2013 has become corrupted and I want to re-install it. However, the uninstaller program refuses to work. How can I remove Office and start again without having to reinstall Windows?
HELPROOM ANSWER Microsoft has a 'Fix it' that you can download to solve this problem. Go to support.microsoft.com/kb/2739501 and then click the Fix it button to download a small utility which will hopefully uninstall Office 2013 for you. Run the utility and wait. It will take a little time.
If this doesn’t work for you, you may have to remove Office manually. The steps required are also provided on the same page from Microsoft.