A family of Microsoft word processing software products for creating web, email, and print documents.
Do you have the original installation media AND Product Key? If you do, you might uninstall Office 2007 and then re-install it. If you have the installation media, but not the Product Key, download the free BelArc Advisor and use it to create an inventory of your system. The inventory will include details of the installed applications and their Product Keys, where applicable.
If you have neither, you are probably out of luck as, because it is no longer supported, Microsoft do not make Office 2007 available for download.