Which tool would you use to troubleshoot issues with open file backups in Windows?

Using the Services tool to troubleshoot issues with open file backups in Windows is appropriate because this tool allows you to view and manage the various services that run on your system, including those related to file backup and protection. Open file backups often require specific services to be active and properly configured, such as the Volume Shadow Copy Service (VSS). If there are issues with these services not running or encountering errors, it can directly affect the ability to back up files that are currently in use. By checking the status and configurations of relevant services, you can identify and resolve problems that may be preventing successful open file backups.

The other options do not provide the necessary functionality for specifically addressing issues related to open file backups. Disk Cleanup is focused on freeing up space on a hard drive and does not involve backup processes. Backup and Restore is more about creating and managing backups rather than troubleshooting them. Windows Defender is a security tool aimed at protecting the system from malware and does not intersect with backup functionalities.