An overwhelming majority of writers use Microsoft Word to save their writing in progress. Except for a few rare exceptions, Word Perfect died long ago as a favorite tool.
Another tool seems to be gaining momentum. Scrivener is being used by some bestselling novelists and screenplay writers because of it’s storyboarding and organizational features. And the text easily exports to e-book formats.
Don’t let the low $40 ($45 for Mac) cost fool you into thinking it’s not a first-rate tool. And for thirty days, you can try it for free.