Office 2021 Professional Plus download: the official installer and how to activate it
The safest Office 2021 Professional Plus download is the official Microsoft installer. This guide shows where to get it, how to install it on Windows 10 or 11, and how to enter your product key. No third-party downloads, no cracks.
Watch: download, install and activate Office 2021 Pro Plus
Prefer watching? This video walks through the same five steps as the guide below.
Watch on the KRBKeys YouTube channel →
Which Office 2021 do you need?
Office 2021 comes in several editions and they are not interchangeable: a key for one edition will not activate another.
| Edition | Apps | Runs on |
|---|---|---|
| Professional Plus 2021 | Word, Excel, PowerPoint, Outlook, OneNote, Access, Publisher | Windows 10 / 11 only |
| Home & Business 2021 | Word, Excel, PowerPoint, Outlook, OneNote | Windows or Mac |
| Home & Student 2021 | Word, Excel, PowerPoint, OneNote | Windows or Mac |
This guide covers Professional Plus 2021 for Windows. On a Mac you need Home & Business 2021 for Mac instead. See the Office 2021 for Mac download guide for the Mac steps.
Before you install
Office 2021 Professional Plus download and install (official Microsoft file)
Microsoft publishes the Professional Plus 2021 installer as a disc image on its own download servers. This is the quickest way.
- Download the official image: ProPlus2021Retail.img from officecdn.microsoft.com (about 3.5 GB, English). It comes straight from Microsoft’s CDN.
- Double-click the downloaded
.imgfile. Windows mounts it as a virtual DVD drive. - Open that drive and run
Setup.exe. Office installs on its own; it takes 5 to 15 minutes. When it says it’s finished, close the window and right-click the virtual drive → Eject.
C:Office, save the configuration below as configuration.xml in that folder, and run setup.exe /configure configuration.xml from an administrator Command Prompt. Change en-us to fr-fr, de-de, es-es, ar-sa and so on.<Configuration>
<Add OfficeClientEdition="64" Channel="PerpetualVL2021">
<Product ID="ProPlus2021Retail">
<Language ID="en-us" />
</Product>
</Add>
<Display Level="Full" AcceptEULA="TRUE" />
</Configuration>Activate with your product key
- Open Word. If a sign-in window appears, click “I have a product key” or “Enter a product key instead”; otherwise go to File → Account → Change Product Key.
- Type the 25-character key from your order email and click Activate.
- The Account page should now say Product Activated · Microsoft Office Professional Plus 2021. That’s it, no Microsoft account required.
Questions and common problems
Where can I download Office 2021 Professional Plus?
From Microsoft. The download button above is Microsoft’s own Office 2021 Professional Plus installer image (ProPlus2021Retail.img) on officecdn.microsoft.com, the same file Microsoft’s servers deliver. Open it, run Setup, then activate with your key.
Is the Office 2021 Professional Plus download free?
The installer is free to download, but Office is not free to use: without a valid product key it shows “Unlicensed Product” and most editing features are switched off. A genuine Office 2021 Professional Plus key is a one-time purchase, with no subscription.
Which apps are included?
Word, Excel, PowerPoint, Outlook, OneNote, Publisher and Access. Publisher and Access are not in Office 2024, so Office 2021 Professional Plus is the version to choose if you need them.
“This product key is not valid”
Nine times out of ten the installed edition doesn’t match the key (for example a Home & Business install with a Pro Plus key). Check File → Account for the exact edition name, and see our step-by-step fix: Office 2021 product key not valid.
Office keeps asking me to sign in
Click “Enter a product key instead” at the bottom of the sign-in window. A retail Pro Plus 2021 key activates locally; it does not need to be linked to a Microsoft account.
Can I move it to a new PC later?
Yes. The license is for one PC at a time. Uninstall on the old machine, install on the new one with the steps above and enter the same key. If activation refuses because the key was used, contact us with your order number and we’ll help.
Is Office 2021 still supported?
Microsoft ended support for Office 2021 on October 13, 2026, so it no longer receives security updates. It keeps working and stays activated, and you can still install the final updates through File → Account → Update Options. If you want security updates for years to come, choose Office 2024 LTSC, which Microsoft supports until October 2029.
