Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
To continue opening and editing .pub files, obtain a legitimate perpetual Windows license for Office Professional 2021 that explicitly includes Publisher, then redeem and install it using the Microsoft account associated with that license.
Get the correct edition
- Office Professional 2021 for Windows includes Publisher; Home & Student 2021 and Home & Business 2021 do not. The consumer license is a one-time purchase for one Windows PC.^1^
- Publisher is Windows-only; it is not included in Office 2021 for Mac.
- Office 2024 does not include Publisher. Because Office 2021 is an older product, availability may be limited to remaining stock from retailers. Verify that the listing names Office Professional 2021, includes Publisher, and supplies a valid perpetual license—not a Microsoft 365 subscription, volume-license key, or account being resold.
- For a workplace-managed computer, ask the IT administrator whether the organization already owns Office LTSC Professional Plus 2021 through volume licensing. LTSC is intended for organizations and is not the normal home-user purchase route.^2^
Redeem, install, and activate
After purchasing a valid license:
- If supplied with a product key, go to
https://office.com/setup. - Sign in with the Microsoft account that should own the license and redeem the key. This permanently associates that copy with the account.
- Open the Microsoft account dashboard and sign in with the same account.
- Select Office apps, locate Office Professional 2021, and select Install.
- Run the downloaded installer and approve the Windows permission prompt.
- Open Publisher or another Office application, accept the license terms, and complete activation if prompted.^3^
You can later confirm the installed edition in Publisher under File > Account.
If Microsoft 365 is already installed
Do not assume that the complete Office Professional 2021 suite can safely coexist with Microsoft 365 on the same PC. Microsoft states that subscription and non-subscription Office versions generally cannot run together; overlapping Click-to-Run installations can cause setup, activation, update, or file-association problems.^4^
The safer choices are:
- Install Office Professional 2021 on a separate Windows 10 or Windows 11 PC; or
- Replace the Microsoft 365 desktop installation on that PC with Office Professional 2021, understanding that this removes the subscription edition’s continuously updated desktop apps; or
- Use a separate Windows virtual machine if comfortable managing one.
Back up the Publisher files before changing any Office installation.
What happens after October 2026
Microsoft 365 subscribers will lose access to Publisher as its removal rolls out after October 1, 2026. A perpetual Publisher 2021 license can still be installed and used afterward, and it can continue opening and editing Publisher files, but support for Publisher 2021 ends on October 13, 2026. It will no longer receive security fixes or technical support.^5^
For long-term protection:
- Keep the original
.pubfiles and a backup on another drive or cloud storage. - Export completed publications through File > Save As > PDF.
- Keep editable copies where practical. Converting through PDF to Word can alter layouts, particularly documents containing many graphics.^5^
References
- Office 2021 and Office LTSC for Windows and Mac FAQ | Microsoft Support
- Overview of Office LTSC 2021
- Download and install or reinstall Office 2021, Office 2019, or Office 2016 | Microsoft Support
- Install and use different versions of Office on the same PC | Microsoft Support
- Microsoft Publisher will no longer be supported after October 2026 | Microsoft Support