The sfc /scannow command will scan all protected system files, and replace corrupted files with a cached copy that is located in a compressed folder at %WinDir% \System32\dllcache. The %WinDir% placeholder represents the Windows operating system folder. For example, C:\Windows.

System File Checker is a utility in Windows that checks for problems with files on your computer. To run it, follow these steps: Make sure you've installed the latest updates for Windows, and then restart your machine. To find out more, read Update Windows.

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.

You'll find direct links to downloadable packages that contain driver and firmware updates for Surface devices. You'll also find a section about imaging for IT professionals. To prepare for updates: Attach your Surface Type Cover or Surface Dock (if you have one) so it gets the latest updates, too. Make sure you have an internet connection.

Learn how to recover files that have been lost, deleted, or accidentally changed.

Use the Quick Assist web app to get help with your computer directly from Microsoft support agents. The app connects your computer with the Microsoft support agent’s computer using a remote connection. The Microsoft support agent will give you a security code—enter it when prompted.

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

Find out how to submit a request for a refund for a purchase of digital Xbox content.

First, you'll need to download the troubleshooter. Download troubleshooter. If you see the File Download box when you start downloading, select Run or Open. The troubleshooter provides steps for you to follow. If a program isn't listed in the uninstall options, you'll be asked for that program's product code.

Learn how to use Windows File Recovery app to restore or recover lost files that have been deleted and are not in the recycle bin.