Actually nothing seems to be active? I had only 1 window open and started CCleaner, but once it came up after the UAC dialog, neither it nor the other window was active. In any case, forgetting about other apps, why can't CCleaner ensure that its own main window is activated on startup?
I run CCleaner (latest 3.x version, portable), click Yes in the UAC dialog, and then I can't simply use the keyboard (press Alt+A for example to Analyze), since the main app window is not the active one! What's the possible reason for this strange behavior? When I run a program, I expect it to be the current active window so that I can start using it immediately, instead of having to Alt+Tab to it or click the main window with the mouse every time.