Windows Error Checking is a built-in tool in the Windows operating system that helps users identify and fix file system errors on their hard drives. It scans the disk for issues such as corrupted files or bad sectors, which can lead to data loss or system instability. To use Windows Error Checking, users can right-click on a drive in File Explorer, select Properties, and navigate to the Tools tab. From there, they can click on "Check" to initiate the scan. This process helps maintain the health of the drive and ensures smooth operation of the system.