Running Windows 7 Pro on I5 laptop, Wi-Fi connected to the Internet.
After loading, CCleaner first displays a blue button "Run Cleaner", then it's grayed out (while checking for updates?), then becoming blue when ready for use.
If I click on the grayed-out button, CCleaner locks up: Windows task manager is then required to End Process. It does not happen every time, but has repeated sufficiently often over the last year or so to become quite irritating.