It appears that Control-Alt-C is consumed by GExperts, despite not being configured as the key combination for an active tool. Reported at https://en.delphipraxis.net/topic/451-new-features-in-gexperts/?do=findComment&comment=6555
This prevents the use of this combination to open the CPU debug window.
I cannot reproduce this in Delphi 2007. Which Delphi version are you using?
And what does the GExperts -> Keyboard Shortcuts expert show for Alt+Ctrl+C on your installation?
Neither can I reproduce it in Delphi 10.3.1.
Many apologies, I believed the original report without testing it myself, so wasted your time. My only excuse was that it seemed to fit the facts, since I have used GExperts for so long, and also been annoyed by the inability to select the CPU window while debugging, but not so annoyed that I had made time to track it down! It turns out that the culprit is MMX Code Explorer, and it is not a bug there, because it shows up in their keyboard shortcut list and is easy to redefine.
I don't have MMX Code Explorer, and I explicitly tested it by disabling GExperts, then reenabling it again, as in my initial bug report:
My Delphi version is DXE3: 17.0.4770.56661
I made another test: if I explicitly assign Alt+ü (which I know is used by nothing else) to "Copy Raw Strings", then the bug goes away. So disabling it (unticking the checkbox in " GExperts -> Configuration -> Editor Experts") seems to have no effect, and is likely the cause for the bug.
Ideally, though, the shortcut would not conflict with predefined IDE ones. Thanks for pointing out the excellent tool " GExperts -> Keyboard Shortcuts".
Last edit: Maël Hörz 2019-03-18
OK, so it seems that keyboard shortcuts are still active even though the expert is disabled. Great, that should be possible to fix.
Last edit: Thomas Mueller 2019-03-18
fixed in revision #2600