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Unhide columns

Windows shortcut 
CtrlShift0
Mac shortcut 
0

Unhide any hidden columns that intersect the current selection.

Notes:

(1) May not work in Excel 2010 on Vista or Windows 7. Discussion and fix is here: http://superuser.com/questions/183197/whats-the-keyboard-shortcut-to-unh...

(2) May not work in Excel 2007. See http://www.techrepublic.com/blog/microsoft-office/office-solution-keyboa...

(3) In Windows 10, there is a conflict with a keyboard switching shortcut. You can resolve by un-assigning the keyboard layout hot key. You may need to un-assign the input language as well.

Windows 10 Change Key Sequence hotkey dialog box

This is a tricky setting to find. You are looking for Advanced Keyboard Settings, under Region and Language. 

Related videos

Tip: Shortcuts to hide/unhide rows and columns
In this video, we look at the shortcuts you can use to hide and unhide both columns and rows. These are very handy for hiding data you don't need to see, and just a taste of Excel's 200+ shortcuts.