Sign in with the Microsoft account used for the February 20, 2023 purchase and reinstall or activate the Office product listed under Services & subscriptions, rather than trying to redeem its key again.
Recover the Office purchase
- Open Services & subscriptions and sign in with the Microsoft account used for the purchase.
- Locate Microsoft 365 or Office, then select Install.
- Open Word or Excel after installation and sign in with that same account when prompted.
- If the purchase is not listed, open Order history, find the February 20, 2023 order, and select Product key/install or Install Office. Microsoft documents both recovery paths here: ^1^
If Office says “This product key has already been used,” do not enter the key again. That normally means it was previously redeemed and attached to a Microsoft account; install and activate by signing in with that account instead.^2^
A one-time Office license only activates its matching release—for example, an Office 2019 license cannot activate a newer Office release.^3^
If the recent update broke Office
The correct rollback method depends on the device:
- Windows: Microsoft’s rollback procedure applies to Microsoft 365, Office 2024, or Office 2021 installed with Click-to-Run; it does not apply to MSI installations. It requires choosing a known earlier build, using the Office Deployment Tool, and temporarily disabling updates. Reverting also removes later security, reliability, and performance improvements.^4^
- Mac: Do not use the Windows Office Deployment Tool. If the Mac runs macOS Big Sur 11, installing an older Microsoft 365 build no longer restores full activation; Office can enter reduced-functionality/read-only mode. The supported paths are upgrading macOS or using Microsoft 365 on the web.^5^
Because the operating system, Office edition, and exact error were not provided, a specific older installer or build cannot safely be identified yet.
Use Microsoft’s official support page and select Get help for Office → Download, install, or activate. It can offer self-help, chat, or the appropriate contact method. The same page lists telephone numbers by country or region.^6^
Have these ready:
- February 20, 2023 order number
- Microsoft account used for the purchase
- Windows or macOS version
- Exact Office product shown in Order history
- Exact error message or screenshot
Do not post the product key, order number, or account details publicly.
References
- [Windows](https://support.microsoft.com/accounts-billing/find-and-install-your-microsoft-downloads-from-microsoft-store#installing-microsoft-365)
- "This product key has already been used" error in Office | Microsoft Support
- Why is my office no longer working? - Microsoft Q&A
- How to revert to an earlier version of Office | Microsoft Support
- I need an older version of Office to run on my MAC - Microsoft Q&A
- Contact Microsoft customer support | Microsoft Support