I have a 3rd party text file "Archs.shx" that I've used over the various versions of AutoCad LT for Windows and Mac a recently as the 2013 for Mac version.  However, I can never remember where to place it in a newly installed software.  The older DWG files now open with "Simplex" as the substituted text style in lieu of "Archs".  I would appreciate any advise.  Thanks.