Reinstall Microsoft Office using a trial copy of the software and the activation key from the previous copy. Back up all important files before reinstalling to prevent the loss of important data.Continue Reading
Connect an external hard drive or USB drive to the computer. Copy all Office documents and settings to the drive. This ensures that your data is secure in the event that something goes wrong during the reinstall process.
Locate the 25-character product key that came with your copy of Office. This key is printed on the package if you bought Office on a disk. It is included in an email if you purchased Office in the form of a digital download.
Insert the Office disk, and double click it. If you don't have a physical copy of Office, download a trial version of Office from the Microsoft website. Navigate to the saved download, and click it to start the installation.
When asked if you want to register the software, click Yes. Enter the product key in the boxes provided and click Continue. Complete the install wizard to finish reinstalling Office, then copy the documents and settings you saved back to your computer.