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 函数成对使用。

Important: Before trying any of the solutions below, make sure you back up your personal files. You can back up your Windows PC, or insert a USB drive and use File Explorer to drag and copy important files to the USB drive.If you’re signing into Windows with a Microsoft account, your system settings will be automatically restored after updating, once you’re connected to the internet.

Battery Life: Lowering your refresh rate can save battery power by reducing the amount of energy your display consumes.This can be useful when you are using a laptop or tablet and want to extend your battery life.

Buy stuff from Microsoft Store online (from your mobile device, on Xbox One, in the Microsoft Store app on your Windows 10/11 or Windows 8.1 device, or via the web).

When prompted, enter the product key. You can find the product key on the sticker on the CD case or other packaging. If you need help, see Find your Product Key for Office 2007.

若要在 Windows 11 中检查激活状态，请选择“开始 ”按钮，然后选择“设置 > 系统 ” ，然后选择“激活 ”。 。 激活状态将在“激活”旁边列出。 在“设置”中检查激活状态. 你将在“激活”页面上看到以下一条激活状态消息：

How to enable TPM. If you need to enable TPM, these settings are managed via the UEFI BIOS (PC firmware) and vary based on your device. You can access these settings by choosing: Settings > Update & Security > Recovery > Restart now. From the next screen, choose Troubleshoot > Advanced options > UEFI Firmware Settings > Restart to make the changes.

To access your sign-in options, go to Start > Settings > Accounts > Sign-in options.. Or just select this button: Go to Sign-in options. Change or manage your password or PIN. To change your password or PIN, go to Start > Settings > Accounts > Sign-in options. Select PIN (Windows Hello), and then select Change PIN.

Argument name. Description. lookup_value (required). The value you want to look up. The value you want to look up must be in the first column of the range of cells you specify in the table_array argument. For example, if table-array spans cells B2:D7, then your lookup_value must be in column B.. Lookup_value can be a value or a reference to a cell.. table_array (required)

Windows Security provides built-in security options to help protect your device from malicious software attacks. To access the features described below, tap the Windows Start button, type windows security, select it from the results, and then select Device security.