Fix Office Product Key Already Used & Installation Stuck at 0%
Question details
The user is unable to activate and install Microsoft Office because the product key purchased from a third-party website reports as already used, and the installation process freezes at 0%.
- Product
- Microsoft Office
- Device & OS
- not provided
- Scenario
- Attempting to redeem an Office product key and install the software suite on a computer.
- Observed behavior
- The setup.office.com portal shows the product key is already used, and any subsequent attempt to reinstall the software results in the installation progress bar being stuck at 0 percent indefinitely.
Ensure you have the login credentials for the Microsoft account you used when first redeeming the key, and verify your internet connection is stable.
Install Office Directly from Your Microsoft Account
A valid product key becomes permanently linked to your Microsoft account upon its first redemption, so you do not need to enter the key again for reinstallation.
Many users encounter the 'already used' error because they attempt to redeem the key a second time instead of installing the software from their account. Once linked, the key is no longer needed.
Navigate to account.microsoft.com/services in your web browser and sign in with the exact Microsoft account you used during the initial redemption.
Scroll through the 'Services & subscriptions' section to find your purchased Office product (e.g., Office Home & Student 2021 or Microsoft 365).
Click the 'Install' button next to your Office edition to download the official setup file directly, bypassing the product key prompt.
Fix the Stuck Installation Using the Uninstall Tool
If your Office installation is permanently stuck at 0 percent, lingering corrupted files or background services from a previous Office installation are likely blocking the setup.
Avoid Activation Hassles with WPS Office
If your third-party Office key turned out to be invalid or the installation remains hopelessly stuck, consider switching to WPS Office. It provides a highly compatible, feature-rich alternative to Microsoft Office without the frustrating activation hurdles and heavy installation files.
- 1. Download WPS Office: Visit the official WPS website to download the free, lightweight installer.
- 2. Install Quickly: Run the setup file. The installation process is streamlined and finishes in just a few clicks.
- 3. Open Your Documents: Launch WPS Office and instantly open, edit, and save your existing Microsoft Office files without compatibility issues.
Frequently Asked Questions
Why does my new Office key say it is already used?
If you purchased a key from a third-party or unauthorized seller, they sometimes distribute the same key to multiple buyers. If another user redeemed it first, it becomes permanently linked to their Microsoft account, triggering this error.
Can I use an activation tool to bypass the product key issue?
No. Using unofficial KMS or third-party activation tools is highly discouraged. They often contain malware, violate Microsoft's terms of service, and can severely destabilize your operating system.
Why is my Office installation stuck at 0%?
This commonly happens due to a slow network connection, interference from third-party antivirus software, or corrupted leftover files from a previous Office installation blocking the new setup.
Do I need my product key every time I reinstall Office?
No. Once a product key is successfully linked to your Microsoft account during the initial setup, you only need to sign in to account.microsoft.com/services to download and reinstall your Office suite.
