How do adjust the width of the columns in the register?

Question

splasher · Answer

With the two line register, only the columns on the top line are changeable.

Tom Young · Answer

Roll your mouse arrow from left to right within the names of the columns at the top of the register.  An arrow with arrowheads at both ends on the line that separates the names will indicate what columns are available for adjustment.  Left click to grab the line and move it.