Some Office 2019, Office 2016, and Office 2013 products come with a product key. If yours did, before installing Microsoft 365 for the first time, sign in with an existing or new Microsoft account and enter your product key at office.com/setup. Redeeming your key is what links your account with Microsoft 365 so you only have to do this once.

If you already redeemed a product key, you're simply reinstalling the apps, or you know you have an assigned license through work or school, you can skip ahead and go to the section sign in to download and install Microsoft 365 or Office.

Having trouble connecting to your email from Outlook on your desktop? Follow these steps to let Outlook diagnose and fix errors in your Outlook mail profile that might be causing the issue.

All Outlook Data Files (.pst) and Offline Data Files (.ost) are listed along with the name of the account the files are associated with. If you cannot open your Outlook data file or suspect that the file is damaged, use the Inbox Repair tool (scanpst.exe) to repair errors in the file.

If you need to install or reinstall the OneNote desktop app on Windows (formerly called “OneNote 2016”), do the following: Download OneNote. When finished downloading, double-click the downloaded file to begin Setup.

Download and install or reinstall Microsoft 365 or Office 2021 on a PC or Mac. Set up Office apps and email on a mobile device. Small business help and learning. Learn how to download and install apps you need from your Microsoft 365 business subscription.

Learn how to remove malware from your PC. Use Microsoft Defender Antivirus in Windows 10 or Windows 11 to scan your PC for malware, viruses, or other threats.

Download the offline installer from your account portal. To download the offline installer, go to www.office.com. If you're not already signed in with the Microsoft account associated with your copy of Microsoft 365 or Microsoft 365 do that now.

The Program Install and Uninstall troubleshooter helps you automatically repair issues when you're blocked from installing or removing programs. It also fixes corrupted registry keys. First, you'll need to download the troubleshooter. Download troubleshooter.

There are different ways to remove apps and programs, so if you can't find the one you're looking for, you can try another location. Note that some apps and programs are built into Windows and can't be uninstalled. You can try to repair a program first, if it's just not running correctly.