Left mouse click the CCleaner icon located at the top-left, a menu should show giving you the option to Close.
The old tricks are the best!! I bet many have forgotten that you can do this at the left hand side of some windows , especially the operating system windows
since Windows 8 when they forgot to put the X in the top right corner (now fixed with 8.1) I had to get all re-acquainted with some long lost keyboard shortcuts.
There's another additional problem: Even programs build-in in Windows 7 itself (is this confined to Windows 7 only ???? Does this happen in Vista, Win 8 & 8.1 as well ???) don't Always properly recognize the fact that the Task Bar is placed on the left hand side of the screen. Then the left hand edge of a program's GUI is placed at the left hand edge of the screen and then the Task Bar is placed on top of the GUI. The Task Bar then effectively hides the most left hand part of a program's GUI.
I am not sure whether or not this is a bug in Windows 7 itself or that programs fail to recognize the fact the Task Bar being on the left hand side of the screen.
My problem is probably related; since update to 5.00.5050, I can't access the Check for updates button on my laptop. I don't know how to move the display higher on the screen. I've tried Ctrl+minus; no joy. The left panel has a giz-whiz to go up or down in that pane, but not the main screen. I have a work-around; I also have a desktop which has a larger screen so I can check for the latest update. I figured I could uninstall and re-install if a new version comes out but there should be a better way. Please advise.