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Microsoft 365 または Office 2021 を PC または Mac にダウンロードしてインストール、または再インストールし ...
インストールの準備. 作業を始める前に、ご利用の PC または Mac がシステム要件を満たしていることを確認します。. プロダクト キーを既に使用している場合は、アプリを再インストールするか、職場または学校でライセンスが割り当てられていることがわかっている場合は、先に進んで ...
Applies To: Office 2021, Office 2021 for Mac, Office 2019, Office 2019 for Mac, Microsoft 365 for home, Office for business, Office 365 Small Business, Microsoft 365 admin, Office 365 operated by 21Vianet, Office 365 operated by 21Vianet - Admin, Microsoft 365 for Mac, Office 365 Germany - Enterprise, Office 365 Germany - Enterprise admin, Office.com
Use System Restore - Microsoft Support
Use System restore to make restore points when you install a new app, driver, or Windows update, and when you create a restore point manually. Restoring won’t affect your personal files, but it will remove apps, drivers, and updates installed after the restore point was made. To go back to a restore point:
Open Device Manager - Microsoft Support
In the search box on the taskbar, type device manager, then select Device Manager from the menu.
Upgrade to Windows 10 Pro - Microsoft Support
Windows 10 Pro offers more advanced security and business networking features, including: BitLocker Drive Encryption
Fix Ethernet connection problems in Windows - Microsoft Support
On your home router. Try these things first to help you fix or narrow down the connection problem. Check the Ethernet cable and connection.Make sure the Ethernet cable is securely plugged into the Ethernet port on both your router and Windows 11 PC.
Create a recovery drive - Microsoft Support
Note: Recovery drives created and used on machines with the April 9, 2024 security update and the revocation policy applied may be impacted.For more, see KB5025885: How to manage the Windows Boot Manager revocations for Secure Boot changes associated with CVE-2023-24932.
Install the latest updates for Windows - Microsoft Support
Windows 11 automatically downloads and installs updates to make sure your device is secure and up to date. This means you receive the latest fixes and security updates, helping your device run efficiently and stay protected.
How to recover a hacked or compromised Microsoft account
If you have a good antivirus program installed, make sure it's up to date and then do a full scan of your system. If you don't have an antivirus app installed on your PC, Microsoft offers some solutions if you're running Windows 8.1 or Windows 10/11. If you're running Windows 8.1 or Windows 10/11, you already have Windows Defender.
Fix network connection issues in Windows - Microsoft Support
Try these things to troubleshoot network connection issues in Windows 11. Make sure Wi-Fi is on. Select Start > Settings > Network & internet, then turn on Wi-Fi.Next, select More options (>) next to Wi-Fi, then select Show available networks.If a network you expect to see appears in the list, select it, then select Connect. Open Wi-Fi settings
Recall an email message that you sent in Outlook
Message recall is available after you select Send and is available only if both you and the recipient have a Microsoft 365 or Microsoft Exchange email account in the same organization.Messages sent to or from a Hotmail, Gmail, or live.com account can't be recalled.
Applies To: Outlook for Microsoft 365, Outlook 2021, Outlook 2019, Outlook 2016, Microsoft 365 admin, Outlook on the web, Outlook.com, New Outlook for Windows