When I download the latest update, it fails to install saying there is a problem with C:\Profgram Files\CCleaner\CCleaner64.exe. It says that there was an error opening file for writing. I have deleted previous download and downloaded anew but it always fails at this point.
If I ignore the error when I run CCleaner, I receive the error "unable to start correctly (0xc000142)"
Make sure ccleaner (and monitoring in taskbar) are fully exited
And then try install
also double check you are getting v5.30.6065 which was an 'emergency' release due to an update issue.
available here; http://www.piriform.com/ccleaner/builds
It says that there was an error opening file for writing
Also make sure files in the CCleaner folder are not marked as read-only.