Windows Disk Cleanup is a built-in utility in the Windows operating system designed to free up space on your hard drive. It scans your computer for unnecessary files, such as temporary files, system cache, and old installation files, allowing you to delete them safely. This helps improve system performance and can make your computer run more efficiently. To use Windows Disk Cleanup, simply search for it in the Start Menu and select the drive you want to clean. After the scan, you can review the list of files and choose which ones to remove. Regular use of this tool can help maintain your system's health.