Problems while running CCleaner for Windows

This page can help you if you have a problem with the way CCleaner is cleaning, plus if it's triggering warnings from an antivirus or firewall program, or you're having some specific issues with Windows user accounts. 

1. Files or folders you have selected are not being cleaned:

As well as adding files or folders to the Include section of the Options area Options > Include, you also need to tell CCleaner you want to clean custom files and folders. You can do this in the Custom Clean section before you run a clean:

  1. In CCleaner, click the Custom Clean icon at left.
  2. Under the Windows tab, in the Advanced section, select the Custom Files and Folders checkbox.

2. CCleaner shows that certain items are skipped when cleaning:

When CCleaner detects that certain programs are running, typically browsers, you get prompted to close these programs, as CCleaner requires your permission to close these programs. If the Do not show me this message again option is checked, CCleaner becomes unable to ask for this permission and cannot close the open browsers.

You can be prompted for this even if the browser(s) appears closed, as they may be running in the background.

To allow these dialogs to be shown again, please visit the Options > Advanced section of the software and click Restore default settings. This resets all settings in the CCleaner software, including the Cookies to Keep list and Include/Exclude lists but allows these prompts to be displayed again, allowing you to ask CCleaner to close open browsers again.

3. You cannot clean other user accounts on your computer:

CCleaner Free only cleans the current user account on your computer. If you want to clean other user accounts, you would need to upgrade to CCleaner Professional. Once upgraded, you can select other user accounts in Options > Users

4. You see a warning from ZoneAlarm firewall or Comodo Antivirus:

ZoneAlarm is a common security program, as is Comodo Antivirus. It checks for suspicious program behavior and alerts you if an unknown program starts to ask for access to system files or the internet.

If you run CCleaner for the first time when you have these programs installed on your computer, you may see an alert on either of them. You may also see an alert when CCleaner checks for an update. Click Allow in the alert to let CCleaner continue.

To avoid seeing any more alerts from your security software about CCleaner, or if there is no Allow in the alert, please make an exception for CCleaner in the security software. You may need to do this in multiple areas depending on the detection being made.

Note: We continuously test CCleaner to ensure that it contains no spyware or adware.

5. You see a User Account Control dialog box when you run CCleaner:

Modern Windows versions use the User Account Control (UAC) feature to prevent users from accidentally running spyware or malware or making major changes to how Windows runs (see here for more information). It does so by asking you to confirm when you are about to run certain programs.

When you start CCleaner, you may receive a UAC warning. Click Continue to use CCleaner.

By default, CCleaner is set to ask Windows not to show a UAC warning; if you see a UAC warning when running the software, please check in CCleaner’s Options > About section and verify if Skip User Account Control Warning is checked or not. 

6. Files that you didn’t want to delete get deleted:

No version of CCleaner has an undo functionality; this would essentially defeat the purpose of the software by preventing it from reducing the amount of space used on the device and make it so that these 'undo files' would contain the same personal data you're trying to erase for the sake of privacy. 

However, you can use our Recuva software to undelete some or all of these files. However, if you performed a Secure Overwrite or wiped the drive's free space in CCleaner, then the files are likely to be lost.

You can download the latest version of Recuva for free. 


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