但如果需要测试多个条件，例如我们假设所有条件都需要为 True 或 False (AND)，或只有一个条件需要为 True 或 False (OR)，或者如果想要检查某个条件是否不 (NOT) 符合你的条件，这时该怎么做呢？这三个函数均可以单独使用，但它们更常见于与 IF 函数成对

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.

Download your Word document as a PDF. Exporting your document as a PDF is a convenient way create a shareable copy of your document while preserving its formatting.

你的安装已经完成时，会看到“都准备好了！Visio 现已安装” ，然后会播放动画来向你介绍在电脑上查找 Visio 应用的位置。 按照窗口中的说明操作以查找 Visio。 例如，根据你的 Windows 版本，选择“开始”，然后向下滚动，从你的应用程序列表中找到 Visio。

如何在 Excel 中将两个或多个单元格中的文本或数据合并为一个单元格。 首先选择要合并的单元格。 使用逗号分隔要合并的单元格，使用引号添加空格、逗号或其他文本。

Safe mode starts Windows in a basic state, using a limited set of files and drivers. If a problem doesn't happen in safe mode, this means that default settings and basic device drivers aren't causing the issue.

借助提示和资源自行进行疑难解答以解决 Windows 蓝屏错误；如果你需要更多帮助，请联系 Microsoft 支持。 如果某个严重问题导致 Windows 意外关闭或重启，则会出现蓝屏错误（有时也称为黑屏错误或终止代码错误）。

To find touchpad devices, select Human Interface Devices or Mice and other pointing devices, then right-click the device you'd like to update.

由于此网站的设置，我们无法提供该页面的具体描述。

Windows Update recommends a reinstall after an update installation fails. If an update fails to install because of problems related to system files or components, you might see the following message in the Windows Update page in Settings:. Reinstall your current version of Windows to repair system files and components.