Downloads OK but install consistently fails in two browsers (Firefox and IE-11).
Err msg - "err opening file for writing" C:\pgmfiles\ccleaner\ccleaner64.exe
Also similar err msg while updating Defraggler
Bewildered Bob
UPDATE - err msg probably caused by CCleaner monitoring. Both "active" and "system" monitoring were in effect while update was attempted. Killing both monitoring activities allowed update to complete normally.