Tcl wasn't installed properly

[Steve]

I'm a frequent user of matplotlib on my Windows XP machine.  I
recently attempted to install a program that modified my Tcl
installation, and I now get an error message when I attempt to plot
anything in matplotlib.  Here is the error message:
---
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python25\lib\lib-tk\Tkinter.py", line 3758, in _test
    root = Tk()
  File "C:\Python25\lib\lib-tk\Tkinter.py", line 1647, in __init__
    self.tk = _tkinter.create(screenName, baseName, className,
interactive, want
objects, useTk, sync, use)
_tkinter.TclError: Can't find a usable init.tcl in the following
directories:
    {C:\Program Files\Tcl\lib\tcl8.3} {C:\Program Files\Tcl\lib
\tcl8.3} {C:/Prog
ram Files/Tcl/lib/tcl8.4} C:/Python25/lib/tcl8.4 C:/lib/tcl8.4 C:/
library



This probably means that Tcl wasn't installed properly.
---
I attempted a complete reinstall of python (hoping it would reinstall
Tcl with correct file paths), but I get the same error.  Any
suggestions would be appreciated.
Thanks!