Word Undo key (Ctrl + Z) is not valid workaround

Recently translated a new book, Word2013 used more, so found a strange problem, the Undo button has been gray. The editor flashed and turned gray. Pressing CTRL-Z also does not work. Chinese resources inside the solution is to use Winword.exe/safe to start once, and then into Word back to normal (such as this article). But this method is not once and for all. I checked the English resources and found a way to change the registry.

Close all programs that are running.


Press Win-r, type regedit in the Run box, and then click OK.


In Registry Editor, expand to the following registry subkey:
Microsoft Office Word 2013
Hkey_current_user\software\microsoft\office\15.0\word\options




On the Edit menu, point to New, and then click DWORD Value. Select New Value #1, type undohistory, and then press Enter.


On the Edit menu, click Modify.


In the Edit DWORD Value dialog box, click Decimal under Cardinality. In the Value box, type a value between 0 and 100, click OK, and then quit Registry Editor. This value is the number of undo, it is not recommended to set too large, generally set to 10. Too much memory resources are occupied by the Assembly.


Start Word. Word stores the undo history in accordance with the number of operations that you specified in step 6.

Word Undo key (Ctrl + Z) is not valid workaround