How to install and activate Office 2021: a step-by-step guide

After you buy from Licono, you receive a 25-character product key by email within minutes. To activate Office 2021, redeem that key on the official Microsoft page, download and install Office, then open Word or Excel and either sign in or enter the key. Every step is explained below.

What you need before you start

The whole process usually takes ten to fifteen minutes. Have the following ready so everything works on the first try:

• The email from Licono with your 25-character key (in five groups of five).
• A free Microsoft account. If you do not have one yet, you can create it while redeeming the key.
• A stable internet connection for the download and activation.
• Enough disk space: count on roughly 4 GB of free space.
• Windows 10 or Windows 11. Office 2021 does not run on older Windows versions.

Important: first remove any Microsoft 365 trial or older Office installation. A leftover trial is the most common reason activation fails later. You can remove it under Settings > Apps > Installed apps.

How do I install Office 2021?

With a retail key, you redeem the key online first and then download the installer from your account. Follow these steps:

1. Open the email from Licono and copy your 25-character product key.
2. In your browser, go to setup.office.com (or to account.microsoft.com and choose Services and subscriptions).
3. Sign in with your Microsoft account or create a new free account. Use an email address you can find again later.
4. Type or paste your product key into the field and confirm. Your key is now linked to your account.
5. Click Install to download the installer.
6. Open the downloaded file (usually in your Downloads folder) and let the installation finish completely without shutting down your computer.

Once the message “You’re all set” appears, Office 2021 is on your PC. You will find Word, Excel, PowerPoint and Outlook in the Start menu.

How do I activate Office 2021 with a product key?

With a retail key, activation is often already handled because you linked the key to your account when you redeemed it. If it does not happen automatically, activate it like this:

1. Open Word or Excel after installation.
2. If a sign-in screen appears, sign in with the same Microsoft account you linked the key to.
3. If you are asked for a key, type your 25 characters carefully and confirm.
4. Check activation under File > Account. Below the product name it should read Product Activated.

If it says “Product Activated”, Office is fully and permanently activated on this PC. There is nothing more you need to do.

Installing and activating Office 2021 Professional Plus (volume key)

Office 2021 Professional Plus often ships with a volume key. The steps then differ slightly from the retail version: you do not link the key to a Microsoft account but enter it only after installation.

1. Download and install Office using the download link or installation package you received with your order. Close all other Office programs during the install.
2. After installation, open Word or Excel.
3. Go to File > Account and click Change Product Key.
4. Enter your 25-character key and confirm. Office briefly contacts Microsoft’s activation server.
5. Check again under File > Account that it reads Product Activated.

Not sure which type you have? The email from Licono states which edition you bought. If in doubt, try the retail method via setup.office.com first. If that does not work, use Change Product Key instead. Your 25 characters work with exactly one of the two routes.

How do I check whether Office 2021 is activated?

Want to be sure everything is in order? Open Word or another Office program and go to File > Account (in Outlook this is called File > Office Account). On the right you see the product name with the activation status below it. If it reads Product Activated, you are done. If you see a warning or a button to activate instead, run through the activation steps above again. Under About on the same page you also find the version and whether you use the 32-bit or 64-bit build, useful if support asks for it.

Office 2021 activation not working? Here is how to fix it

Most activation problems are quick to solve. Work through these points calmly:

• Message “The product key you entered doesn’t work”: retype the key and watch for confusing characters. A 0 (zero) is not an O (letter), and a 1 is not an I or L. Preferably copy straight from the email, without extra spaces at the start or end.
• A trial or older Office is blocking activation: remove Microsoft 365 trials and old Office versions under Settings > Apps, restart the PC and try again.
• Wrong build (64-bit versus 32-bit): if you install Office separately, choose the version that matches your system. 64-bit is the default on modern PCs.
• Activation server is busy: wait fifteen minutes and try again. This is almost always temporary and clears up on its own.
• Wrong key type used: if redeeming on setup.office.com does not work, use File > Account > Change Product Key instead (and the other way around).
• No internet during activation: Office needs to go online once to activate. Turn off a VPN or a strict firewall temporarily and try once more.

If Office still will not activate, our support team is happy to help. Keep your order number and the exact error message at hand, and we usually get it sorted quickly.

“Free Office without a key”: why you should skip it

Online you will find plenty of tricks to activate Office “for free” with a crack or a KMS tool. That is not a real licence. Such activations are not legitimate, can suddenly stop working after an update, and expose your PC to malware that is often hidden inside those tools. On top of that, you breach Microsoft’s terms of use.

A genuine key is the clean solution: it is valid, keeps working, and you get an invoice including VAT. At Licono we sell only genuine, legally resold licences, delivered by email within minutes and with clear installation instructions included.

Frequently asked questions about Office 2021

Does Office 2021 work without a subscription? Yes. Office 2021 is a one-time purchase. You pay once and use the programs on your PC for good, with no monthly or yearly cost. You do not get new major versions, but you do receive the regular security updates.

On how many PCs may I use one key? An Office 2021 licence is meant for one PC. If you want Office on several computers, you need a key per computer. If you replace your PC, a retail licence can usually be transferred to the new device.

I can no longer access my Microsoft account, what now? With a retail key, your licence is linked to your account. If you cannot sign in, first recover your account via account.microsoft.com. With a volume key the account does not matter: you activate directly with the key under File > Account.

Can I choose the language and build? Yes. While downloading from your account you choose the language and the build. By default you get your system language and the 64-bit build.

In short

Installing and activating Office 2021 is not hard: redeem your key or enter it after installation under File > Account, then check that it reads “Product Activated”. Choose a genuine key and Office 2021 keeps working, with no subscription and no risk. If you do get stuck, our support is ready to help.