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:

You can use installation media (a USB flash drive or DVD) to install a new copy of Windows, perform a clean installation, or reinstall Windows. To create installation media, go to the software download website, where you'll find step-by-step instructions.

Install Microsoft 365 2019 or 2016 on a PC. Remember a one-time purchase version of Microsoft 365 is licensed for one install only. Depending on your browser, select Open file (in Edge or Internet Explorer), Setup (in Chrome), or Save File (in Firefox).

How malware can infect your device. Microsoft security help and learning. If you suspect that your device may have malware you should have Microsoft Defender run a scan. Here's how to do that on Windows, Mac, or Android.

If you can't sign in to your Outlook.com, Hotmail, Live, or MSN email account, or you're not sure how to sign in or sign out, here are some solutions.

To connect your controller with Xbox Wireless, you might need the Xbox Wireless Adapter for Windows. If your PC has Xbox Wireless built in, you can connect the controller directly without an adapter. If you’re using the Xbox Wireless Adapter: Plug the Xbox Wireless Adapter into your PC.

Learn how to add user accounts in Windows 10 and Windows 11. With an account, each person has separate files, browser favorites, and a private desktop.

To use Microsoft 365 on your new device, you can activate Microsoft 365 as a 1-month trial of Microsoft 365 Family. You can also buy Microsoft 365 or a non-subscription version of Office, add Microsoft 365 to an existing Microsoft 365 subscription, or enter a product key from a new product key card.

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.

Windows 11. PC Health Check app brings you up to date info on your Windows device health, helping you take action to improve your device performance and troubleshoot performance problems. It is periodically updated based on customer feedback to help you make the most of your Windows PC. How to open PC Health Check.