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:

If some Windows functions aren't working or Windows crashes, use the System File Checker to scan Windows and restore your files. Though the steps below might look complicated at first glance, just follow them in order, step-by-step, and we’ll try to get you back on track. Run the System File Checker tool (SFC.exe)

Automatically update Windows 10, Windows 11, and Surface drivers and firmware (Recommended) Manually update Surface drivers and firmware (Advanced) You'll find the links for drivers after choosing your Surface model in the dropdown list in this section.

Learn how to update your security processor or TPM firmware to protect Windows 10 and your device from attacks by malicious software.

The Program Install and Uninstall troubleshooter helps you automatically repair issues when you're blocked from installing or removing programs. It also fixes corrupted registry keys. First, you'll need to download the troubleshooter. Download troubleshooter.

If you can't find an app or program, try the tips in See all your apps in Windows 10 and Program is not listed in add/remove programs after installation. If you get an error message when you're uninstalling, try the Program Install and Uninstall Troubleshooter.

For Windows 8.1, see Create a USB recovery drive. To download Windows 11 installation media, see Recovery options in Windows. Create a recovery drive so you can reinstall Windows 10 or Windows 11 in case you experience a major issue such as hardware failure.

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.

Create Windows 11 installation media. On the Windows 11 software download page, select Create tool now and follow the instructions to install Windows 11. Warning: Microsoft recommends against installing Windows 11 on a device that does not meet the Windows 11 minimum system requirements.

On the Windows 10 download page, download the media creation tool by selecting Download now, then run the tool. In the tool, select Create installation media (USB flash drive, DVD, or ISO) for another PC > Next. Select the language, architecture, and edition of Windows, you need and select Next.