What you need to do before moving Microsoft Office
Moving Microsoft Office to another computer depends on what you own and how you bought it. If you have a Microsoft 365 subscription (formerly Office 365), you can sign into your new computer and read Office there—your license moves with your account. If you own a one-time purchase license like Office 2021 or Office 2019, you'll need to uninstall it from the old computer first, then install it on the new one using your product key. The product key is a 25-character code that came with your purchase or in a confirmation email.
The first step is to figure out which version you have. Open any Office program on your current computer, click File, then Account. If you see "Subscription" at the top with a renewal date, you have Microsoft 365. If you see "Product Activated" or a product key field, you own a one-time license. Write down or screenshot whichever applies—you'll need this information on your new computer.
Key Takeaways
- Microsoft 365 subscriptions move automatically when you sign in on a new computer; one-time licenses require you to uninstall from the old computer first.
- You can find your product key in your Microsoft account, in the original confirmation email, or on the product card that came with your purchase.
- Uninstalling Office completely from your old computer before installing on a new one prevents license conflicts and ensures the new installation works.
- If you have multiple computers, Microsoft 365 lets you install on up to five devices at once, though you can only use it actively on one at a time.
Moving a Microsoft 365 subscription to your new computer
If you have a Microsoft 365 subscription, the process is straightforward. On your new computer, open a web browser and go to office.com. Sign in with the Microsoft account you use for your subscription. Click Install apps (or Install Office, depending on your region), then choose Install next to the Office process. Your browser will read the installer file.
Run the installer file and follow the on-screen prompts. Office will install and automatically set up using your account credentials. You don't need a product key. Once installation is complete, open any Office program and sign in with the same Microsoft account. Your subscription is now active on the new computer. If you want to remove Office from your old computer, you can do that anytime—your subscription will still work on the new one.
If you have multiple computers, Microsoft 365 allows you to install on up to five devices. However, you can only actively use Office on one computer at a time. If you try to use it on two computers simultaneously, you may be asked to sign in again on one of them.
Moving a one-time Office license to your new computer
One-time licenses like Office 2021 or Office 2019 are tied to a single computer. Before you can install on a new computer, you must uninstall it completely from the old one. On your old computer, go to Settings (Windows) or System Preferences (Mac), find Apps or Applications, locate Microsoft Office, and select Uninstall. Follow the prompts to remove it entirely.
Once uninstalled, you'll need your product key to install on the new computer. If you don't have it written down, check your Microsoft account. Go to account.microsoft.com, sign in, and look for Services & subscriptions or Devices—your product key may be listed there. If you bought Office in a store, check the product card or the original email confirmation. If you can't find it anywhere, contact Microsoft Support with proof of purchase.
On your new computer, read Office from office.com or use installation media if you have it. During installation, you'll be prompted to enter your product key. Type it in exactly as it appears—it's 25 characters with hyphens. After installation completes, Office will set up and you're done. The license is now on your new computer.
Finding your product key if you've lost it
If you bought Office through the Microsoft Store or Microsoft's website, your product key should be in your Microsoft account. Sign in at account.microsoft.com, go to Services & subscriptions, and look for Office. Your key may be displayed there or available to copy. If you bought it from a retailer like Best Buy or Staples, check your email for the original order confirmation—the key is usually in that message.
If you bought a physical copy, the product key is on the card inside the box or on the back of the packaging. If the box is long gone and you can't find the email, you can contact Microsoft Support. Have your proof of purchase ready—a receipt, credit card statement, or order number. They can verify your purchase and provide the key.
Uninstalling Office from your old computer
On Windows, go to Settings, click Apps, then Apps & features. Scroll down and find Microsoft Office. Click it, then click Uninstall. A dialog will appear asking you to confirm—click Yes. The uninstall process may take several minutes. When it's done, restart your computer.
On Mac, open Finder, go to Applications, find Microsoft Office, and drag it to the Trash. Then empty the Trash. Some Office files may remain in your user Library folder, but these won't interfere with a new installation on another computer. If you want to remove them completely, you can use the Microsoft Office removal tool, which you can read from Microsoft's support website.
What to do if Office won't install on your new computer
If you see an error message during installation, the most common cause is that Office is still registered to your old computer. Make sure you fully uninstalled it there first. Restart both computers and try again. If you're moving a one-time license, double-check that you entered the product key correctly—it's case-sensitive and must include the hyphens.
If you're using a Microsoft 365 subscription and installation stalls, sign out of your Microsoft account on the new computer, restart it, then sign back in and try installing again. If Office still won't set up after installation, go to File > Account and click Sign in to re-authenticate your account. If problems persist, contact Microsoft Support—they can check your account status and help troubleshoot.
Frequently Asked Questions
Can I use the same product key on two computers at once?
No. One-time licenses are tied to a single computer. You must uninstall from the old computer before installing on a new one. If you need Office on multiple computers, Microsoft 365 is designed for that—it lets you install on up to five devices, though you can only use it actively on one at a time.
What happens to my files if I uninstall Office?
Your Word documents, Excel spreadsheets, and other files remain on your computer. Uninstalling Office only removes the programs themselves, not the files you created. Your documents will still be there; you just won't be able to open them until you reinstall Office or use a free viewer like Office Online.
Do I need internet to install Office on my new computer?
Yes, you need an active internet connection to read and install Office. For Microsoft 365, you also need to sign in with your account during installation. If your new computer doesn't have internet yet, you can read Office on another device, transfer it via USB drive, and install it offline—though you'll still need to sign in online at some point to set up it.
Can I transfer Office from a work computer to my personal computer?
No. If your employer provided Office, it's licensed to your work account and computer only. Installing it on a personal computer violates the license agreement. If you need Office at home, you'll need to purchase your own Microsoft 365 subscription or one-time license.
What if I'm moving to a Mac from Windows, or vice versa?
Office for Mac and Office for Windows are separate installations. If you have a Microsoft 365 subscription, you can install on both—just sign in on each computer. If you have a one-time license, check whether it's valid for both platforms; most are not. You may need to purchase a separate Mac license. Contact Microsoft Support with your product key to confirm.