O&O DiskCleaner
The integrated O&O DiskCleaner finds temporary and unnecessary files so you can reclaim space before optimization. Open O&O DiskCleaner in the ribbon. Review its settings below the drive list before starting cleanup.
Analyze first
- Select the drive.
- Review the enabled file categories in DiskCleaner settings.
- Click Analyze.
- Review the settings table and File overview report when analysis finishes.
- Adjust the selection before choosing Clean.
Analysis finds candidates for deletion. It does not by itself confirm that you no longer need diagnostic files, cached data, or Recycle Bin contents.
File categories
| Category | What to consider |
|---|---|
| Temporary files | Application and system temporary data; files in use can remain unavailable. |
| Temporary Internet files | Cached content; applications may need to download it again. |
| Downloaded Windows updates | Leftover update installation data offered by the cleaner. |
| Memory dumps | Can occupy substantial space but may be needed to diagnose a crash. |
| Windows error reports | Diagnostic information that may still be useful for troubleshooting. |
| Thumbnails | Cached previews; rebuilding them can temporarily slow browsing. |
| Setup log files | Installation diagnostics; retain them while investigating setup problems. |
| Windows Indexing Service cache | Removing it can require rebuilding the search index and temporarily affect search. |
| Recycle Bin | Contains deleted items you may still want to restore. Cleanup permanently removes them. |
Review the selected categories before cleanup, especially the indexing cache and Recycle Bin. Keep diagnostic files and recoverable items that you need.
Clean and verify
Choose Clean after reviewing the categories and results. You can pause or stop cleanup, but this does not restore files already deleted. Files locked by Windows or another process can remain untouched.
After completion, inspect the timeline and detailed report to see what was removed. The result can differ from the analysis if files were locked, deleted, or changed in the meantime.
In the current Modern UI, cleanup is provided through separate Tools. Use those instructions when your window does not contain the integrated DiskCleaner ribbon.