Check for Windows updates. Learn how to update drivers in Windows using Device Manager to update or reinstall a driver.

Microsoft .NET Framework 4.8.1 is a highly compatible and in-place update to .NET Framework 4.8. It includes native support for the Arm64 architecture (Windows 11+), accessibility improvements as well as other improvements. For a complete list of improvements see: .NET Framework 4.8.1 release notes.

Some Office 2019, Office 2016, and Office 2013 products come with a product key. If yours did, before installing Microsoft 365 for the first time, sign in with an existing or new Microsoft account and enter your product key at office.com/setup. Redeeming your key is what links your account with Microsoft 365 so you only have to do this once.

A BitLocker recovery key is needed when BitLocker can’t automatically unlock an encrypted drive in Windows. This key, which is a 48-digit number, is used to regain access to the drive. You might be prompted for the BitLocker recovery key during startup, due to a security risk or hardware change:

The Microsoft .NET Framework 4.7.1 is a highly compatible in-place update to the Microsoft .NET Framework 4, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, and 4.7. The offline package can be used when the web installer cannot be used because of lack of Internet connectivity.

The Microsoft .NET Framework 4.8 is a highly compatible, in-place update to the Microsoft .NET Framework 4, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1 and 4.7.2. The offline package can be used in situations in which the web installer cannot be used because of lack of Internet connectivity.

Learn more about our Xbox subscription refund policy. You can receive a refund within 30 days of your initial purchase or before your first recurring billing date (whichever is sooner) by canceling your subscription in the steps that are outlined in the section “Canceling a subscription.”.

Installation media, such as a USB flash drive, can be used to install a new copy of Windows, perform a clean installation of Windows, or reinstall Windows. To create installation media, go to the software download website, where step-by-step instructions can be found.

Microsoft .NET Framework 4.6.1 是 Microsoft .NET Framework 4、.NET Framework 4.5、.NET Framework 4.5.1、.NET Framework 4.5.2 和.NET Framework 4.6. 由于缺少 Internet 连接，无法使用 Web 安装程序 时，可以使用脱机安装程序。

Microsoft .NET Framework 4.6 是 Microsoft .NET Framework 4、.NET Framework 4.5、.NET Framework 4.5.1 和 .NET Framework 4.5.2 的高度兼容的就地更新。 为了获得最佳效率和带宽要求，Microsoft 建议尽可能使用 Web 安装程序而不是脱机包。