Installation issues for CCleaner for Windows

If you are having problems with installing CCleaner, this page can help you. We walk you through why Windows Administrator permissions are important and the errors that can occur if a file gets damaged during the download process or if the 'Error opening file for writing' message appears in Windows.

Why Windows Administrator permissions are important:

We recommend that you install and use CCleaner with a Windows User Profile that has Administrator permissions. This is needed for the software to perform all the requested tasks successfully. 

NSIS errors:

1. What NSIS errors are:

There are a few different kinds of NSIS errors, but these almost always occur when an installer file gets damaged when you download it from the internet.

2. What you can do to fix them:

Usually, you can correct these errors by deleting the damaged file and then downloading it again. You may want to wait a little while before doing so. This is in case it's due to internet connection problems, etc. 

If you continue to have issues, it may also be worth contacting your internet service provider and asking them to test your internet connection to see if there are problems with it.

Error opening file for writing (Windows error message):

This is an error message that can appear on your Windows computer. It can affect any third-party application and stop it from being installed. It can sometimes occur when you update the CCleaner app's software. 

1. Correcting this error: 

You need to stop all of CCleaner's running processes manually using these steps.
  1. Open the Windows Task Manager (On the keyboard, hold the Ctrl, Shift, and Esc keys simultaneously)
  2. Open the Processes tab
  3. Right-click on the processes associated with
    • CCleaner
    • CCleaner64
  4. (and any other processes related to CCleaner or ccsetup)
  5. Click End Process > End process

2. Start the installation process again:

Try installing CCleaner again once you've completed 1. Correcting this error above. If you continue to have problems, you can also try uninstalling the existing version of CCleaner. Restart the computer via the Start menu (on the Windows taskbar) to complete the uninstallation process and install CCleaner again. This should ensure that the conflicting file is no longer present and unable to cause any further problems.


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