A family of Microsoft word processing software products for creating web, email, and print documents.
Click the big Office button in the upper left corner of the Word window.
Click Word Options (it's near the bottom).
Select Advanced in the navigation pane on the left hand side of the Word Options dialog.
Scroll down to the Display section.
There is a box labeled "Style area pane width in Draft and Outline view".
Enter a non-zero value in this box, e.g. 1" or 2.5cm.
Click OK.
The style area will now appear in Draft view and in Outline view, and as you indicate, it can easily be made wider or narrower by dragging its right edge with the mouse.