There is a simple solution.
Use Options/Advanced / "Save settings to INI"
Close CCleaner AFTER you have defined (without using) an Include of C:\
Open the folder holding CCleaner.exe
and then use Notepad to edit CCleaner.INI and change something like
Include1=PATH|C:\
and change it to something like
Include1=PATH|C:\Windows\System32\config\systemprofile\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\
and save this file.
N.B. '1' in "Include1" may be a bigger number if there are other Includes also defined.
When you next launch CCleaner it should correctly target this special folder that most of us were unaware of.
If you wish you can now cancel Options/Advanced / "Save settings to INI"
and your settings will then be held in the registry and should still target this special folder.
Personally I always use the Portable version of CCleaner because I hate using the registry.
The problem was that after I downloaded Explorer 10 two months ago, temp files were downloaded to this file location:
C:\Windows\System32\config\systemprofile\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5
That relationship is tenuous.
I have never at any time allowed Internet Explorer to run on my Windows 7 Ultimate,
but I have exactly the same path.
It is a Windows thing, or possibly a Trident thing.
On my system that path holds only one folder with two files totalling 18 KB
C:\Windows\System32\config\systemprofile\AppData\Local\Microsoft\Windows\Temporary Internet Files\Content.IE5\892A5CK9\
The two files are both dated 27 July 2013, 12:27:59
They are
desktop.ini
and
IDR_XML_DEFAULT_TRANSFORM[1]
I have just used Locate32 and found all the files modified around that time, and the guilty party is
C:\ProgramData\Microsoft\Windows\Power Efficiency Diagnostics\energy-ntkl.etl etc.