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How I free up Windows disk space and shred sensitive data for free with open-source BleachBit
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Want to free up hard disk space on your Windows PC? Sure, the built-in Storage Sense feature can tackle that task. But it doesn't offer much control or flexibility over what to delete. Instead, I use a free Windows utility called BleachBit. With this open-source tool, you can review potentially unnecessary files for certain installed apps and Windows features, and then choose what to remove.
For example, you can opt to delete the cache, cookies, history, passwords, or other data from your web browser or the backup files, history, and logs from Windows Defender. The goal is to give you control over what to keep and what to remove. As an added bonus, you can securely shred sensitive or confidential folders and files so that they can't be recovered.
Also: My 5 favorite Windows Insider features in 2026 so far
Before we proceed, a word of warning. Any third-party utility that aims to clean up or otherwise optimize your Windows PC should be used with caution. The wrong change could disable a specific application or feature or remove content you want to retain, such as browser cookies. You always want to preview any planned changes to see their impact before you pull the switch. That's especially true with a product like BleachBit, which doesn't let you undo your changes.
Before you try to clean up or optimize Windows through a utility, I recommend that you use the built-in System Restore tool to create a restore point. If any problems occur as a result of the changes, you can recover Windows through a previous restore point.
BleachBit supports both Windows 10 and 11 as well as Linux, as covered in this story by my ZDNET colleague Jack Wallen. Here's how I use it in Windows 11 and how you can as well.
1. Download and install BleachBit
Browse to the BleachBit website and click the Download button. Select the option to download it for Windows. Be aware, though, that the download can be tricky since you have to navigate through a few screens and ads. Launch the app after installation and you'll see the main screen with a list of the apps and features for your review.
2. Review the list
Scroll down to see all the apps and features listed. On my PC, BleachBit showed me a diverse lineup of installed apps, including Adobe Reader, Brave browser, Claude AI, Firefox, Microsoft Office, Slack, and Zoom. The utility displays different elements for each one, such as backup files, cache, recently used items, logs, history, and temporary files.
Beyond showing you individual apps, BleachBit covers Windows features and settings. Among these are entries for Explorer and Windows Defender. There's also one for System that highlights the clipboard, Recycle Bin, temp files, update installers, and log files. Another entry called Deep scan dives into hidden and orphaned files, backup files, and other leftover files.
3. Select the change for a specific entry
Next, you'll want to test the process with one entry. To choose all the content for that entry, check the box next to the entry's name. To choose only specific elements, check the box for the item you want to remove. A warning symbol next to any item means that the option is protected, and you'd have to use BleachBit in expert mode to select it.
4. Preview the changes
Select a specific entry or individual items and then click the Preview button. BleachBit displays a list of all the files that would be removed if you proceeded. Review each file to find out what would be deleted.
For example, I previewed changes for the System category. Upon reviewing the results, I found that most of the files to be deleted were temp files, system dumps, and files in the Recycle Bin. If you're not familiar with a particular file, you may want to run a separate web search on it to learn what it does.
Also: How to remap the Windows 11 Copilot key
Scroll to the bottom of the list to see how many files would be removed and how much disk space would be recovered. If the list shows any files that you don't want removed, uncheck the related element and run the preview again. Also, if the amount of disk space you'd free is minimal, then you may not want to proceed with this entry.
5. Remove the files
Your next step is to remove the files. Click the Clean icon at the top and then click the Delete button to confirm your action. After the cleanup, BleachBit shows you how many files were deleted and how much disk space was recovered. From there, you can use your PC normally.
6. Shred folders or files
Deleting a folder or file in Windows doesn't physically remove the data from your hard drive. By default, deleted items are sent to the Recycle Bin where they remain until the bin becomes full. Even then, a file can often be restored through a recovery utility, especially if its clusters haven't yet been overwritten by other data. With BleachBit, you can shred a sensitive folder or file to make sure it can't be recovered.
To do this, click the icon in the upper left and select "Shred Files" or "Shred Folders" from the menu. At the File Explorer window, navigate to and select the folders or files you wish to shred and then click Open. BleachBit will ask if you want to permanently delete these files. Click Delete to proceed.
BleachBit offers other options, including a way to wipe all free disk space, run the tool in expert mode, and exclude cookies and other files from being deleted. You can investigate these options and more by clicking the icon in the upper left and selecting Preferences.
Overall, BleachBit is an effective way to selectively free up disk space and securely erase confidential files. I've run it several times, and it did get rid of unnecessary files with no ill effects. But again, you need to be cautious. Always back up your system or create a restore point before you use it.