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.

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:

進一步了解有關 Xbox 數位代碼和禮品卡，以及如何疑難排解兌換內容的問題。

Change from a 32-bit version to a 64-bit version or vice versa. Activate Windows. Fix Bluetooth problems in Windows. Learn how to install, reinstall, or activate Microsoft 365 or Office 2019 on a PC or Mac.

瞭解如何在行動裝置、Windows 裝置或 Xbox 主機上兌換 Microsoft/Xbox 禮品卡或其他代碼。

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.

Remote Assistance Support from Microsoft allows a Microsoft support professional in another location to view your computer screen and work on your computer over a secured connection. Protect yourself from tech support scams. Before clicking 'I accept', review the: Agreement for Microsoft Services. Microsoft Software License Terms.

Why can’t I remove my payment option? Sharing your Xbox Game Pass subscription. Update an Xbox subscription for you or your child. Making sure your Xbox digital subscription is valid for your country or region. Turn on recurring billing for your Xbox subscription. Get help with EA Play for Xbox.

Download and install or reinstall Microsoft 365 or Office 2021 on a PC or Mac. Set up Office apps and email on a mobile device. Small business help and learning. Learn how to download and install apps you need from your Microsoft 365 business subscription.

Contact Microsoft Support. Find solutions to common problems, or get help from a support agent.