No program has the decision-making skills to determine what's safe to delete or not. Make that decision based on your knowledge and experience. If you're in doubt, don't delete the file.
Please read through the usage notes below for some general advice. Thanks.
We recommend scans on specific paths (folders) rather than the drive's root. For many users, a scan of C:\My Documents or perhaps C:\My Documents\My Pictures makes more sense than a scan of C:\ alone.
It will keep the scan away from operating system folders, many of which should not delete because Windows prevents them from being deleted.
As noted above, Duplicate File Finder cannot decide which files are safe to delete or not. It would be best to make that decision yourself, based on your knowledge of the files found. When in doubt, do not delete it!
We recommend doing cleanups in multiple steps. For example, if you organize files by a separate folders project, begin at a lower level folder.
Do a cleanup at that level before moving to a higher-level folder. Taking smaller bites will probably make it easier to be systematic and organized with your cleanup work.
Do not rely on the Windows Recycle Bin as a safety mechanism for large-scale duplicate deletions. DO NOT attempt to clean out files from \Windows folder with the idea that "If something breaks, I can just restore from Recycle Bin." The Recycle Bin is not limitless! Files you put there today may be gone forever after two weeks.