Lost my product key for microsoft

Since the original Microsoft 365/Office account and product key are lost, recovery depends on proof of purchase and whether Office was preinstalled or purchased separately.

Use these steps:

1. If Office came preinstalled on the laptop
   • Many new devices include a 1‑month Microsoft 365 trial only. In that case, there is no perpetual product key, and a paid subscription is required to continue using Office.
   • If a paid Microsoft 365/Office product was included with the PC, the device usually uses a digital product key tied to Windows activation rather than a printed key. When Windows was first activated, a digital key was transmitted to the PC.
   • For help with activation on a new or reset PC in this scenario, follow: Get help with activating an Office purchase or free offer on a new PC.
2. If there was a physical product key card
   • Check whether there is a product key card that came with the laptop. The key is in the format XXXXX-XXXXX-XXXXX-XXXXX-XXXXX and may be under a scratch‑off foil. If the foil was damaged and the key is unreadable, see step 3.
3. If the product key is lost or damaged
   • If there is valid proof of purchase (invoice, receipt, order confirmation), Microsoft support may be able to replace the product key or provide other options.
   • Go to Microsoft support and open a support request about a lost or damaged Office product key, providing device details, serial number, and proof of purchase.
4. If the product key or license no longer works
   • If the key was purchased separately (for example, from an online seller) and now fails, it may have been blocked as stolen or fraudulent. In that case, the guidance is to contact the seller and request a refund and then obtain a new, genuine license.
5. If the old Microsoft account cannot be accessed
   • The Office license is typically bound to the original Microsoft account used for redemption. If that account cannot be recovered, support is required to review options. Use the Microsoft support contact page above and provide all purchase and device details.

If none of the above paths work and the original license cannot be recovered or validated, a new Microsoft 365 subscription or Office license will be required to activate Office on the reset laptop.

References:

• Using product keys with Microsoft 365
• Find your product key for Office 2010