I am on Windows 10 Home office 2013. I went in a file this morning and I could not open it because Excel is gone. and word. I found my product key, but I don't know how to put it back on.

To use the Office 2013 product key again, Office must be reinstalled and then activated with that key.

1. On Windows 10, first check if Office is really uninstalled:
   • Select Start and in the taskbar search box type Word or Excel.
   • If they appear in the results, select them and see if they open.
   • If they do not appear or will not open, proceed to reinstall.
2. Reinstall Office 2013:
   • Use the original Office 2013 installation media or download method that was used when it was first installed (for example, the setup DVD or the original download from Microsoft tied to the Microsoft account used to purchase Office 2013).
   • Run the Office 2013 setup and follow the prompts to install.
3. Enter the product key during setup/activation:
   • During installation or the first time Word/Excel is opened after install, there will be a prompt to enter the Office product key.
   • Type the 25‑character product key that was found and complete activation.

If the product key is not accepted or there are issues with the key, follow the guidance in Where to enter your Office product key and Find your Office product key for more details on using and troubleshooting Office product keys.

After Office is installed and activated, Excel and Word files can be opened again by double‑clicking them or by opening Excel/Word from Start and then using File d�3 Open.

References:

• Find your Office apps in Windows
• Where to enter your Office product key
• Find your Office product key