Step 1: Go to setup.office.com
Step 2: sign in as email@example.com
Step 3: enter the product key
Step 4: choose language/country
Step 5: Download
Step 6: Install using the key
Step 7: Run Word, when challenged for a key enter the key. You may be asked to download an update.
Step 8: Call 866-421-7141 and follow prompts – for best results use the cell phone SMS options, get the link sent to your phone, and then manually type that link on a browser on the PC where office is being installed on. This will let you copy/paste the results and save time/errors.