Changing the Maximum Undo Levels

Rob asked if there is a way to change the maximum number of undo levels in Word. The short answer is, no, you can't. The reason is that you don't need to--the only thing that limits the number of undo levels in Word is the amount of resources you have in your computer. This means that the number of undo levels in Word is, for all intents and purposes, unlimited. In fact, you can run a small macro to show that this is the case. Consider this macro:

Sub TestUndo()
    For i = 1 To 10000
        ActiveDocument.Range.InsertAfter i & " "
    Next i
End Sub

It will take a few moments to run the macro, which inserts 10,000 numbers in your document, but when the macro is done, take a look at your undo stack (click on the down-arrow next to the Undo tool on the toolbar). You will notice that you can undo all 10,000 individual steps.

There are things, however, that will clear the undo stack. For instance, protecting a document for forms, executing the UndoClear method in a macro, or closing and reopening a document.