CCleaner changes the registry in the following manner (I don't think it does it on purpose, but it does none-the-less). I get a Counterspy alert that it's trying to do it, and no matter if I block it, it does it anyway. In one or both of the following keys:
HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
HKLM\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
the Recent value gets changed from an Expandable String Value to a plain String Value the Data being %USERPROFILE%\Recent. When you try to install almost any software from that point on, it cannot install, returns a Microsoft 1606 error. This occurs if the Microsoft Installation Engine is used in the installation. The following URL addresses the problem and the fix:
Microsoft KB886549
Can you please find what causes this and correct it. I had the problem with both version 1.18.099 and 1.19.105.
BTW it took me a long time to find and fix the error as the error message didn't stay on the screen for very long as it errored out, and I couldn't figure what "broke" it.