Also, uncheck "But only files which have not been accessed for in the last..", under the 'Files to Find' and 'More' tab.
NOW IT WORKS, THANKS
and more:
The searchstring=*.tmp
in Options, FileCleaner has to search the c-drive only
RESULT:
I expected the tmpfiles of the c-drive only, but...
shown are all tempdirectories with content on the C:\ and the D:\drive,
and the tmp-files in C:\windows