Why is the CTRL + / not working?

Question

I've learned how to use this shortcut to input fractions in the 2D form, it worked nice on my notebook but I can't make it on my desktop. Any tip on what could be happening?

Answer 1

You are not very specific in your details so I have to guess what may be wrong. I can come up with some possibilities:

Keyboard shortcuts redefined
Keyboard shortcuts are defined in the file KeyEventTranslations.tr. This is located in the directory specified by executing either

FileNameJoin[{$InstallationDirectory, "SystemFiles", "FrontEnd", "TextResources", 
              $OperatingSystem}]

or

FileNameJoin[{$UserBaseDirectory, "SystemFiles", "FrontEnd", "TextResources", $OperatingSystem}]

Shortcut definitions in file in the latter directory (if present) override definitions in in the former.

Search for a line that looks like

Item[KeyEvent["/", Modifiers -> {Control}], "Fraction"],

which defines the fraction shortcut. Check whether this contains the "/" character (default) or something different.

Numeric keypad used
Perhaps you normally use the "/" on the numeric keypad of your desktop. For this key to work the Numlock key needs to be set to the correct state.

OS keyboard setting
Perhaps the keyboard setting of your OS tells your programs that different keys are pressed than what's printed on the key. For instance, if I set the keyboard type of my (physical) US international keyboard to French, pressing the 'q' key gets me an 'a'. You probably have a Brazilian keyboard which is rather unusual. Some versions of Ubuntu seem to have problems with that. My keyboard generates a ";" instead of a "/" when Windows is told it's Brazilian.