Activation helps verify that your copy of Windows is genuine and hasn’t been used on more devices than the Microsoft Software License Terms allow. There are three methods to which you can activate your product: Online via the internet, by telephone using our automated systems, and by a live support advocate.

查找 Windows 7 或 Windows 8.1 的产品密钥. 卸载或重新安装 Windows 7 或 Windows 8.1 时，通常需要产品密钥。 通常，如果购买的是实物 Windows 拷贝，产品密钥应该在标签上或者在 Windows 随附包装盒中的卡上。

即使已开启其他防火墙，开启 Microsoft Defender 防火墙也很重要。 它保护你免遭未经授权的访问。 若要打开或关闭 Microsoft Defender 防火墙，请执行以下操作：

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Get support for all Office.com apps, including Excel, Word, and PowerPoint, with step-by-step guidance and troubleshooting.

This content can help you with your work or school account, which is the account provided to you by your organization (for example, dritan@contoso.com).

如果在 Microsoft Store 中更改所在国家或地区，你在某个地区获取的内容可能无法在另一个地区使用。

了解在 Windows 中查找 BitLocker 恢复密钥的不同方法，并了解如何在系统上激活 BitLocker。

Learn how to recover a hacked or compromised account, what to do next, and how to prevent your account from being compromised in the future.

如果通过 Microsoft 工作区折扣计划 购买了 Microsoft 365. 如果通过雇主的 工作区折扣计划(以前称为家用许可计划) 权益安装 Office 专业增强版、Visio Professional 或 Project Professional，请在安装产品后输入产品密钥。