Get Rid of the Reviewing Pane Quickly
The Problem:
I often edit Word 2003 files with Track Changes, using the Final setting in the Reviewing toolbar so I can see what the edited version will look like. Sometimes when I'm in the midst of editing, I want to insert a comment. After I've done so, Word changes the setting from Final to Final Showing Markup, so I have to change it back again. But here's the real annoyance: when I change back to Final, Word sometimes decides to open the Reviewing Pane at the bottom of the window.
The Solution:
Word has to switch to Final Showing Markup when you insert a comment, because otherwise you won't be able to see the comment. If you're using Print Layout view or Web Layout view and you've selected the "Use balloons in Print and Web Layout" box on the Track Changes tab of the Options dialog box (Tools 
Options), Word displays the balloons in your preferred margin. Otherwise, Word displays the Reviewing Pane for you to enter the comment.
There's no real fix, but here are two quick ways to get rid of the Reviewing Pane: either double-click the bar that splits the Reviewing Pane from the document area or press Alt+Shift+C.