The basic process depends on how you own Office

Microsoft Office transfers differently depending on whether you own a perpetual license (a one-time purchase like Office 2021) or a subscription (Microsoft 365, formerly Office 365). Perpetual licenses let you install on one computer at a time and move them between machines. Subscriptions let you install on multiple devices simultaneously — typically up to five computers — and move between them freely as long as your subscription is active.

The transfer itself is straightforward: you uninstall from the old computer, sign in on the new one, and reinstall. The hard part is knowing which route applies to you and whether you need your product key or just your Microsoft account. If you bought Office years ago and don't remember which version you have, you can check by opening any Office app on your old computer and going to File > Account > About [App Name].

Key Takeaways

  • Microsoft 365 subscriptions move automatically when you sign in on a new computer; perpetual licenses (Office 2021, Office 2019) require you to uninstall first and may need a product key.
  • You can install Microsoft 365 on up to five computers at once, but only use it actively on one at a time per license agreement.
  • Uninstall Office completely from your old computer before installing on the new one if you own a perpetual license and want to avoid activation problems.
  • Your product key is tied to your Microsoft account for newer versions; if you can't find it, you can recover it through your account settings or by contacting Microsoft support.
  • Office on a new computer may require you to reactivate, which happens automatically if you sign in with the same Microsoft account you used to purchase it.

Moving a Microsoft 365 subscription

If you pay a monthly or yearly fee for Microsoft 365 (the subscription that includes Word, Excel, PowerPoint, and other apps), the transfer is the simplest route. Your subscription is tied to your Microsoft account, not to a specific computer. Sign in on your new computer with the same Microsoft account, download Office from microsoft.com, and install it. The apps will activate automatically.

You do not need to uninstall from your old computer first, though you should if you want to free up space. Microsoft 365 lets you install on up to five devices, but you can only use it actively on one computer per license agreement. If you keep it installed on both machines and both are signed in, you are technically in violation — though Microsoft does not actively police this for personal use. The practical limit is that if you sign in on a sixth device, the oldest one will be signed out automatically.

If you are moving to a work computer and your employer provides Microsoft 365, that is a different account and you should not mix it with your personal subscription. Install your personal version on a personal device only, and use your work account on work machines.

Moving a perpetual license (Office 2021, 2019, or older)

Perpetual licenses are one-time purchases that do not expire. You own a license to install Office on one computer at a time. To move it to a new machine, you must uninstall it from the old one first, then install and activate it on the new one using your product key.

Start by uninstalling Office completely from your old computer. Go to Settings > Apps > Apps & Features (or Control Panel > Programs > Programs and Features on older Windows), find Microsoft Office, and select Uninstall. Follow the prompts to remove it entirely. This step matters because Microsoft's activation system will reject a second installation if the first one is still registered to your account.

On your new computer, download the Office installer from microsoft.com or use installation media if you have it (a DVD or USB drive from the original purchase). Run the installer and when prompted, enter your product key. If you do not have the key, you can retrieve it from your Microsoft account if you registered the purchase there, or contact Microsoft support with proof of purchase.

Finding your product key if you have lost it

If you bought Office years ago and no longer have the product key, there are a few places to look. Check your email for a receipt from Microsoft or the retailer where you bought it — the key is usually in that email. If you registered your copy with a Microsoft account at the time of purchase, sign in to account.microsoft.com, go to Services & Subscriptions, and look for Office. Your key may be listed there.

If you still have Office installed on your old computer, you can use a free key-recovery tool to extract it from the system. Search for "Microsoft Office product key viewer" — legitimate tools like Belarc Advisor or Magical Jelly Bean Keyfinder will display your key without installing anything suspicious. Write it down before you uninstall.

If none of those work, contact Microsoft support directly. Have your proof of purchase ready — a receipt, credit card statement, or order confirmation. They can verify you own the license and provide a replacement key, though the process may take a few days.

Reactivating Office on your new computer

After you install Office on your new machine, it will prompt you to activate. For Microsoft 365, this happens automatically when you sign in with your Microsoft account. For perpetual licenses, you will see an activation screen asking for your product key or offering to activate online.

Choose online activation if you have an internet connection — it is faster and does not require a phone call. Enter your product key and sign in with the Microsoft account associated with your purchase. If activation fails, it usually means the key is already activated on another computer. Uninstall Office from that machine first, wait a few minutes, and try again on the new computer.

If you see an error saying your key has been used too many times, you have likely installed it on more than one computer simultaneously (which violates the license agreement for perpetual licenses). Contact Microsoft support to explain the situation. They can reset your key so you can activate on your new machine, though they may ask you to confirm you have uninstalled from the old one.

What to do if your old computer is broken or inaccessible

If your old computer is dead or you no longer have access to it, you cannot uninstall Office from it before installing on the new one. For perpetual licenses, contact Microsoft support and explain the situation. They can deactivate the license on the old machine remotely so you can activate it on the new one. Have your product key and proof of purchase ready.

For Microsoft 365, you do not need to do anything — just sign in on your new computer and install. Your subscription is account-based, not device-based, so it does not matter if the old computer is gone. If you want to be thorough, sign in to account.microsoft.com and check your devices list. You can remove the old computer from there, though it is not required.

Transferring Office files and settings to your new computer

Installing Office on a new computer does not automatically move your files, templates, or custom settings. Your documents are separate from the application itself. If your files are stored in OneDrive or another cloud service, they will appear on your new computer automatically when you sign in. If they are stored locally on your old computer, you need to copy them manually.

Connect an external drive to your old computer, copy your Documents folder and any other folders containing Office files, then connect that drive to your new computer and paste them back. Alternatively, if both computers are on the same network, you can copy files directly between them using File Explorer.

Custom settings like email signatures, templates, or Outlook rules are stored in your user profile and do not transfer automatically. For Outlook, you can export your settings and import them on the new computer. For Word templates, copy the STARTUP folder from your old computer's user profile (usually hidden) to the same location on the new one. The exact path varies by Office version, so search Microsoft's support site for your specific version if you need detailed steps.

Frequently Asked Questions

Can I install Microsoft 365 on multiple computers at the same time?

Yes, you can install on up to five devices simultaneously, but you can only use it actively on one computer per license. If you sign in on a sixth device, the oldest one will be automatically signed out. For household use, this typically means one person per computer, or one person using multiple devices.

What happens if I don't uninstall Office from my old computer before installing on the new one?

For Microsoft 365, nothing — it works fine on multiple devices. For perpetual licenses, activation will likely fail on the new computer because the system sees the key already in use. You will need to uninstall from the old machine and wait a few minutes before trying again on the new one.

Do I need to buy a new Office license for my new computer?

No. Both Microsoft 365 subscriptions and perpetual licenses move with you. You are paying for the right to use the software, not for a specific computer. As long as your subscription is active or your perpetual license is valid, you can install on a new machine.

Will my Outlook email account transfer to the new computer?

Your email account is separate from Office itself. When you open Outlook on your new computer, you will need to sign in again with your email address and password. Your email will download automatically if you are using a cloud-based account like Outlook.com or Gmail. If you use a local email provider, you may need to reconfigure the account settings.

What if I have Office on a Mac and want to move it to a Windows PC?

The license transfers, but you need to uninstall from the Mac first. Download the Windows version of Office on your new PC and activate using the same product key or Microsoft account. The installation files are different between Mac and Windows, so you cannot simply copy the application folder.