Office 2021 Pro Plus ISO: Download in English (32/64-bit)

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ISO Office 2021 Pro Plus en français : télécharger avec l'image .img ou l'ODT

Microsoft does not publish an official Office 2021 Professional Plus ISO for the general public: Office 2021 installs via Click-to-Run, meaning a small program downloads the files from Microsoft's servers. To get an installation in your language, including offline, you have two official methods: the offline installer (.img file) from your Microsoft account when the licence is linked to it, or the Office Deployment Tool (ODT), which downloads a complete, reusable source. In the vast majority of cases, choose the 64-bit version.

At support, the question “where is the ISO?” comes up very often, usually after a download from a third-party site that went wrong. Here is how to get the Office 2021 Pro Plus installation files cleanly, and how to choose between 32-bit and 64-bit.

Is there an official Office 2021 Pro Plus ISO?

Not in the sense of a freely downloadable ISO file, as there is for Windows. Since Office 2016, the consumer version of Office has relied on Click-to-Run technology: the setup.exe file you run does not contain Office; it fetches the components from Microsoft's content delivery network (CDN) and installs them as it goes.

In practice, that leaves three scenarios:

Method Who it's for What you get Offline
Microsoft account (Services & subscriptions) Licences linked to an account Online installer or .img image Yes, with the .img image
Office Deployment Tool (ODT) Any Pro Plus licence, retail or volume An “Office” folder with the source files Yes
Volume Licensing portal Organisations with a volume agreement Files provided by Microsoft to the agreement holder Yes
ISO found on a third-party site Best avoided File of unknown origin Yes, but with no guarantee

What forums often call an “Office 2021 ISO” is therefore either the official .img image renamed, an ODT source repackaged by someone, or a modified file. The first two options can be obtained directly from Microsoft, with no middleman.

How do you download Office 2021 from your Microsoft account?

If your Office 2021 product key has been linked to a Microsoft account (as with Home & Student, Home & Business or “Bind” keys), you download it from account.microsoft.com > Services & subscriptions. Microsoft describes the procedure on its help page on installing Office offline:

  1. Sign in to your Microsoft account and click Install next to Office 2021.
  2. In the installation window, under “Choose a version”, select Offline installer.
  3. Choose your language, for example English (United Kingdom), then click Install and save the .img file.
  4. Double-click the .img file: Windows mounts it as a virtual drive (for example D:).
  5. Open the Office folder on the virtual drive and run Setup64.exe (or Setup32.exe for the 32-bit version).

The .img image can be copied to a USB stick to install another PC without a fast connection. Activation, however, always requires an internet connection on first launch. For the full installation procedure and entering your licence key, follow our guide to download, install and activate Office 2021 Pro Plus.

Steps to download the Office 2021 offline image from your Microsoft account
The official .img image is a better choice than a third-party ISO.

How do you create an offline source with the Office Deployment Tool?

When the Pro Plus licence does not appear in a Microsoft account (key entered directly, MAK licence), the ODT is the most reliable method. It is the official tool we use at support to prepare installations on several computers.

  1. Download the Office Deployment Tool from the Microsoft Download Center, then run it and choose an extraction folder, for example C:\Office2021. You get setup.exe and sample XML files.
  2. In that folder, create a text file named configuration.xml (watch out for the .txt extension hidden by File Explorer) with the content below.
  3. Open a Command Prompt as administrator, then type cd C:\Office2021.
  4. Start the download with setup.exe /download configuration.xml. The window appears frozen for several minutes: this is normal, an Office subfolder of several GB is filling up.
  5. Then install with setup.exe /configure configuration.xml, on this PC or on another one by copying the whole folder.

Example configuration.xml for Office 2021 Professional Plus in English (UK), 64-bit:

<Configuration>
  <Add SourcePath="C:\Office2021" OfficeClientEdition="64" Channel="Current">
    <Product ID="ProPlus2021Retail">
      <Language ID="en-gb" />
    </Product>
  </Add>
  <Display Level="Full" AcceptEULA="TRUE" />
</Configuration>

A few points to watch, drawn from our support tickets:

  • The product ID must match your key: ProPlus2021Retail for a retail key, ProPlus2021Volume for a volume (MAK) key. With the wrong ID, the key is rejected at activation.
  • MAK licence: also replace Channel="Current" with Channel="PerpetualVL2021", the update channel Microsoft requires for Office LTSC 2021.
  • Language: en-gb installs Office in British English (use en-us for US English). You can add a second Language line (for example fr-fr) if you need proofing tools in another language.
  • You can add the attribute PIDKEY="XXXXX-XXXXX-XXXXX-XXXXX-XXXXX" to the Product tag to include the key, which is handy on several computers with a MAK licence.

Other options exist (excluding an application with ExcludeApp, logging, removing an older version): they are documented on Microsoft Learn on the Office Deployment Tool configuration options page.

Office Deployment Tool commands to download and install the Office 2021 ISO offline
Two commands are all it takes: /download then /configure.

Office 2021 32-bit or 64-bit: which should you choose?

Microsoft installs the 64-bit version by default, and it is the right choice for almost everyone. The ODT in fact switches automatically to 32-bit if Windows is 32-bit or the PC has less than 4 GB of memory.

Criterion 32-bit 64-bit
32-bit Windows Required Not possible
Large Excel workbooks, Power Pivot Limited by memory Recommended
Old add-ins or macros with 32-bit API calls Compatible Need updating (PtrSafe)
Older ODBC / Access drivers Often required Depends on the driver
Security and performance Adequate Better

Above all, remember one rule: you cannot mix the two architectures. If a 32-bit Office or Visio is already installed, the 64-bit installation stops with a message such as “We couldn't install the 64-bit version of Office because we found the following 32-bit programs”. You then need to uninstall the older product or stay on 32-bit everywhere. Microsoft details the special cases in its article on choosing between the 64-bit and 32-bit version of Office.

Office 2021 32-bit vs 64-bit comparison to choose the right version to install
64-bit suits the vast majority of recent PCs.

To check the Windows architecture: Settings > System > About, “System type” line. For an Office that is already installed: File > Account > About Word.

What are the prerequisites before installing Office 2021?

  • Operating system: Windows 10 or Windows 11. Office 2021 does not install on Windows 7 or 8.1.
  • Disk space: allow at least 4 GB free for the installation, more if you also store the ODT source on the same drive.
  • No other competing Click-to-Run version: a preinstalled Microsoft 365 or a trial Office can block the installation or cause activation conflicts. Uninstall it first via Settings > Apps > Installed apps.
  • Visio and Project: if they need to coexist with Office, they must have the same architecture and a compatible version.

After a reformat or a change of PC, the logic is the same; we explain it in our article on reinstalling Office 2021 on a new PC.

Are Office 2021 ISOs found online safe?

An ISO downloaded from a file-sharing site or a torrent comes with no guarantee: there is no way to check it has not been modified, and many are “pre-activated”, meaning they ship with a built-in activator. At best you waste time; at worst you install malware with administrator rights. Since the official files are free and only the licence is paid for, there is no reason to go through a middleman. We explain the dangers of activators and “free” keys in our article on free Office 2021 keys and their risks.

Frequently asked questions

Can I put the .img file or the ODT source on a USB stick?

Yes. Simply copy the .img image or the whole folder containing setup.exe, configuration.xml and the Office subfolder. There is no need for a “bootable” stick.

Can I install Office 2021 in one language and switch to another later?

Yes, by adding the language pack you want and then setting it as the default in File > Options > Language. Installing directly in the right language (for example en-gb) is still simpler.

Do you have to pay to download the Office 2021 files?

No. The installation files are provided free of charge by Microsoft; it is the product key that activates the licence.

Do I need the internet to install from the offline source?

Not for the installation itself, but activating the key requires a connection the first time you launch an application.

Does the downloaded source receive updates?

It contains the version available on the day of the download. Once Office is installed, updates are applied normally via File > Account > Update Options. Note that Microsoft support for Office 2021 ended on 13 October 2026, so no new security updates are released after that date.

Get a licence for your installation

The files are official and free; all you need is the key. For a single computer, an Office 2021 Professional Plus licence for 1 PC installs with ProPlus2021Retail; for a fleet of several machines, the Office 2021 Pro Plus MAK licence is used with ProPlus2021Volume and the ODT. Our support team can help you prepare your configuration file.