A family of Microsoft word processing software products for creating web, email, and print documents.
In Word, right click your Ribbon and choose 'Customize the Ribbon'
At the bottom of that dialog, click 'Keyboard Shortcuts' - Customize
In Categories on the left, click 'All Commands'
In Commands on the right, click 'EditCopy'
That is the Keyboard shortcut you need to reset
That's It