1) Move the cursor over a column line in the column title area. You'll see the cursor change.
 
2) When the cursor changes, hold down on the mouse button and move the column line to a new location. In the example below, the right side of the column Hr Rate is being moved to make the column larger.
 
3) Release the mouse button. That's it!
 
Note: if the column will not enlarge, first enlarge the TimeTracker document window, and try again.