Note: If it’s been fewer than 10 days since you upgraded to Windows 10, your previous version of Windows will be listed as a system file you can delete.If you need to free up drive space, you can delete it, but keep in mind that you'll be deleting your Windows.old folder, which contains files that give you the option to go back to your previous version of Windows.

获取 Windows 操作系统的官方支持和帮助信息，以及如何使用 Windows 的指南。

Project Online Professional或Project Online 高级版： 如果你订阅了Project的基于云的解决方案之一，则你将看不到安装它的选项，除非你有分配的许可证。如果你是负责分配许可证的 Microsoft 365 管理员，请参阅向用户分配许可证。

If the app is already open on the desktop, press and hold (or right click) the app's taskbar icon, and then select Pin to taskbar. Note: To remove a pinned app from the taskbar, right-click the app icon, then select Unpin from taskbar .

注意: 使用安装介质重新安装Windows 11，同时选择“不保留任何内容” (干净安装) ，如果重新安装 Windows 的分区为 20GB 或更大，则将自动启用保留存储。保留存储空间将留出磁盘空间以供更新、应用、临时文件和系统缓存使用，因此可确保关键的操作系统功能始终可以访问磁盘空间，从而改进了电脑 ...

Tips: While signing in, select Yes at the "Stay signed in?" prompt if you want to go straight to your mailbox next time (not recommended for shared computers). Alternatively, check the "Don't show this again" box and select No to be prompted for your password each time.. If you can't sign in, or have forgotten your username or password, use our sign-in troubleshooter.

To install Authenticator on your Android device. Scan the QR code. or download and install Authenticator from the Google Play store. Get the app

If you tried all of these steps and are still having issues, we recommend sending your log files for diagnostics. Open the app, go to the app’s top-level menu, and then select Send feedback. After that, contact Support or go to the Microsoft Authenticator app forum and explain the problem you're seeing and the steps you tried.

If you bought a stand-alone version of an Office app, for example Visio or Word, in most cases you install this app in the same way you install the Microsoft 365 or Office suite, by signing in to www.office.com with your Microsoft account, or work or school account and selecting Install for your stand-alone product.

若要在 Outlook.com 中取得支援，請按一下這裡或選取功能表列上的 [說明]，然後輸入您的查詢。如果自助無法解決問題，請向下捲動至 [仍然需要協助嗎?] 然後選取 [是]。 若要在 Outlook.com 中與我們連絡，您必須登入。 如果您無法登入，請按一下 [這裡]。 如需 Microsoft 帳戶或訂閱的其他協助，請瀏覽 ...