Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Since this was originally purchased through the Microsoft Workplace Discount Program, activate Office Professional Plus 2016 this way:
- Open an Office app such as Word.
- In the Sign in to set up Office window, select I don't want to sign in or create an account.
- Enter the Office product key without hyphens.
If the key was already redeemed before, do not redeem it again. Instead, sign in with the Microsoft account that was used when the product was originally redeemed, then install or reinstall Office from account.microsoft.com/services/office/install.
If activation still fails, check for multiple Office installations and remove any version not being used:
- Open Control Panel.
- Go to Programs > Programs and Features.
- Search for office.
- If more than one Office version appears, uninstall the one not being used.
- Restart the PC.
- Open Office again and complete activation.
If the upgraded PC is showing repeated activation prompts and Office is a volume license edition, first verify it shows as Office Professional Plus and has a Change Product Key link under File > Account. If so, a leftover preinstalled Office activation entry may be causing the prompt.
Warning: the next step modifies the registry. Incorrect changes can cause serious problems. Back up the registry first.
- Close all Office apps.
- Press Start, select Run, type regedit, and press Enter.
- Go to:
- HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\16.0\Common\OEM
- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\16.0\Common\OEM
- Export each OEM key as a backup.
- Delete each OEM key.
- Close Registry Editor and start Office again.
For one-time purchase Office editions, Office Home & Business, Office Home & Student, and Office Professional are licensed for one computer. If moved to different hardware and activation limit is reached, phone activation is the documented path after reinstalling, and Office must be uninstalled from the original computer.
References:
- Activate Office for Windows
- Where to enter your Office product key
- Unlicensed Product and activation errors in Office
- Office repeatedly prompts you to activate on a new PC
- Activate Office after reinstalling or installing on a different device
- Download and install or reinstall Office 2021, Office 2019, or Office 2016