Your Office licence arrives by email within seconds of payment, with the product key and a direct link to Microsoft’s own installer. This guide takes you from that email to Word opening with an activated licence.
Remove any existing Office first
This step is skipped more often than any other, and it causes more failed activations than faulty keys do. An existing Microsoft 365 or older Office installation will block a new perpetual licence from activating. Before installing, go to Settings → Apps → Installed apps, find any Microsoft 365 or Office entry, and uninstall it. Restart the machine afterwards. If an install has left fragments behind, Microsoft’s own Support and Recovery Assistant removes them cleanly.
Step 1 — Download the installer
Use the link in your delivery email. It points to Microsoft’s official download for the exact edition you bought, so you do not need to work out which ISO or setup file is correct. Run it and let it complete — the download is several gigabytes and installs in the background, so give it time on a slower connection.
Step 2 — Open any Office application
Once installation finishes, open Word, Excel or any other installed app. Office will prompt you to sign in or enter a product key. Choose the option to enter a product key rather than signing in to a Microsoft 365 account, unless your delivery email specifically told you this is an account-based licence.
Step 3 — Enter your key
Type or paste the 25-character key exactly as it appears in your email. Pasting is safer than typing: a single mistyped character produces a “key is not valid” message that looks like a faulty key but is not one. Office then contacts Microsoft’s activation service and confirms the licence.
Step 4 — Confirm the licence
In any Office app, go to File → Account. Under Product Information you should see the edition you bought and a line confirming the product is activated. If it still shows a trial or a subscription, the old installation was probably not fully removed — go back to the first step.
Common problems and what they mean
- “This product key is not valid for this product” — an edition mismatch. A Professional Plus key will not activate a Home & Student installation. Install the edition your key is for.
- Office keeps asking to sign in — a leftover Microsoft 365 installation is still present. Remove it, restart, then reopen Office.
- Activation limit reached — the key has already been used on the number of devices it covers. Check whether it is still active on an older machine.
- No internet on the machine — use telephone activation. Our free Confirmation ID service handles it for you.
If you are still stuck
Send us your order number and the exact error message or code on screen. That detail usually tells us the cause immediately and saves a round of back-and-forth. Support runs seven days a week, and every order carries our 180-day money-back guarantee — if a key cannot be activated, you get a replacement or a refund.
Browse our Microsoft Office product keys, including Office 2024 and Office 2021.