"...I don't know exactly why but anytime a I install a new update of
Guide the 'toolbar.dat' file contents in the Guide directory are replaced
(once Guide is started) by that of the 'new_tool.dat' file."

You don't really want to eliminate the 'new_tool.dat' results. This
file exists because some toolbar buttons have been added with some
of the updates. (For example, buttons for the "full screen" mode,
new projections, and AVI animation creation, and the next update
will have buttons to recenter on the eight compass points).

If you edit 'toolbar.dat' and look near the end, you'll see a long
discussion of this and other arcane facts about the toolbar file
(how to rearrange buttons, resetting the bitmaps used for buttons,
translating, and so on.)

When Guide detects 'new_tool.dat', it runs through your existing
'toolbar.dat' to determine which buttons are currently turned on,
adjusts 'new_tool.dat' accordingly, then uses it to replace your
old 'toolbar.dat'. In the situation you describe, the best solution
would be to edit 'toolbar.dat' and reset the number of toolbar buttons
(remembering to include all the new buttons.)

WARNING: The number of toolbar buttons is intentionally set low.
The other buttons are either not working or more trouble than they
are probably worth. (For example, there are buttons to "go to"
obscure outer planet satellites, or to zoom in/out 13 levels,
plus a long list of DOS-only buttons for use in the unlikely situation
that I put a toolbar into DOS Guide.) Some are for functions that
are in development (for example, there are "next conjunction"
and a "previous conjunction" buttons that ought to be very useful,
if I ever get them to work properly). Most of these buttons do work,
but be warned that in general, if I had confidence in them, they'd
be up with the "real" buttons.

-- Bill