The Microsoft Excel keyboard shortcut Ctrl+Alt+F5 to Refresh All was one of my favorites until it stopped working. Presently, when I enter that key combination nothing (as far as I can see) happens. I've had to live without it for so long that I can't recall if there was anything specific that was changed prior to it no longer working. Alt+F5 continues to work to Refresh a specific PivotTable, but that has limited value.
The version is Excel 2007.
How can I discover what is preventing Ctrl+Alt+F5 from working and restore its default functionality?
I solved this problem by disabling Intel Graphics hotkeys:
Right-click on the desktop, hover over the menu option "Graphics Options" > "Hot Keys" > click Disable.
I had the exact same issue described above, albeit on Excel 2013 then eventually worked out that the key combination Ctrl+Alt+F5 (as well as other Ctrl+Alt+Fn keys) is reserved by the Intel Graphics control panel. I'd never even noticed this program but it's accessible by right-clicking on the desktop and selecting 'Graphics Properties...'. The Intel Graphics control panel doesn't use Ctrl+Alt+F5 by default, but it still reserves it apparently. I can assure you that disabling the Intel Graphics hot keys allows me to be able to use Ctrl+Alt+F5 in Excel straight away.
Hope that helps!
By the way, this same solution is shown here for a different user problem: https://forums.lenovo.com/t5/W-Series-ThinkPad-Laptops/hotkeys-Alt-Ctrl-F1-Alt-Ctrl-F5-which-pre-install-application/td-p/1318777