Find operating system info in Windows 8.1 or Windows RT 8.1. To find out which version of Windows your device is running, press the Windows logo key key + R, type winver in the Open box, and then select OK.. If your device is running Windows 8.1 or Windows RT 8.1, here’s how to learn more:

To reset your PC, go to Start > Settings > System > Recovery .Next to Reset this PC , select Reset PC.Then, select Keep my files, choose cloud or local, change your settings, and set Restore preinstalled apps? to No.. Open Recovery settings

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.

An upgrade differs from an update in that it moves your PC from a previous version of Windows—such as Windows 10—to Windows 11. This FAQ is intended to answer questions about upgrading to Windows 11.

If you're running Windows 8.1 or earlier, or if your PC doesn't meet the minimum system requirements to run Windows 11, consider moving to a new Windows 11 device. Find a PC that meets your needs. Set up your Microsoft account to transfer files and favorites. One account connects your device across Microsoft apps and services like Microsoft 365, OneDrive, Edge, and Microsoft Store.

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。

How to open the Camera app in Windows. To open up your webcam or camera, select the Start button, then select All apps, and then select Camera in the list of apps. If you have multiple cameras, you can switch between them by selecting Change Camera at the top right once the Camera app is opened.. Open Camera

In Date & time, you can choose to let Windows 10 set your time and time zone automatically, or you can set them manually.. To set your time and time zone in Windows 10, go to Start > Settings > Time & language > Date & time.. Open Date & time settings

Learn how to manage extensions in Microsoft Edge, including adding, disabling, or removing them as needed.

Tips: If you want a deeper scan, instead of selecting Quick scan in step 3, select Scan options and choose the type of scan you want.. For the most complete scan, run Microsoft Defender Offline. For more about that see Help protect my PC with Microsoft Defender Offline.