CCleaner Won't Launch in CCleaner for Mac Posted May 23, 2015 I was having a similar problem. Ccleaner wouldn't launch. But I didn't get any error messages, and it didn't seem like it was crashing. Instead, nothing happened when I tried double clicking or running it as an administrator. This solution posted to a reddit techsupport thread worked for me. [–]agildehaus 3 points 1 day ago Remove any CCleaner entries from: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\ Malware uses a little registry trick to prevent certain apps from opening. You'll likely see regedit in there too.