Unfortunately, there are many dishonest sellers who offer stolen, abused, or otherwise unauthorized Microsoft product keys for sale. If you bought a product key separate from the software, it’s very possible the product key was stolen or otherwise fraudulently obtained, and subsequently blocked for use. If your Office product key doesn’t work, or has stopped working, you should contact the seller and request a refund. If it's hard to read the product key on your packaging, use this guide to help you tell the numbers and letters apart:
If you lose your Product Key and have a valid proof of purchase, contact Microsoft support for help.
Keep the packaging, or write the number down and keep it in a safe place.
