If some Windows functions aren't working or Windows crashes, use the System File Checker to scan Windows and restore your files. Though the steps below might look complicated at first glance, just follow them in order, step-by-step, and we’ll try to get you back on track.

This article explains how you can get or create a digital signature for use in Office documents. To learn more about how to use them in Office documents, see Add or remove a digital signature in Office files.

Learn how to update your security processor or TPM firmware to protect Windows 10 and your device from attacks by malicious software.

Tip: To use or test macro projects on your own computer, you can create your own self-signing certificate by using the Selfcert.exe tool. You'll find more details on that below. Get a digital certificate.

Select Add sign-in method. Select Choose a method and then Authenticator app. Follow the on-screen instructions, including using your mobile device to scan the QR code, and then select Next. You'll be asked to approve a notification through the Microsoft Authenticator app, to verify your information. Select Save.

Follow these steps to automatically diagnose and repair Windows security problems by turning on UAC, DEP protection, Windows Firewall, and other Windows security options and features. Select the Download button on this page.

Learn how to install, reinstall, or activate Microsoft 365 or Office 2019 on a PC or Mac.

To install Microsoft 365 in a different language, or to install the 64-bit version, use the dropdown to find more options. Choose the language and bit version you want, and then select Install. You're now ready to install Microsoft 365 . Select the tab below for the version you're trying to install.

Signing certificate and certificate authority. Signing certificate To create a digital signature, you need a signing certificate, which proves identity. When you send a digitally-signed macro or document, you also send your certificate and public key.

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.