This is done automatically by the INSTALL program unless the user chooses not to. For an explanation of what TACTPATH is, please read on.
TACT programs require various other files during execution, such as XLATTABL.DAT and TACT.RES. Usually these reside in the directory that TACT itself comes from, but sometimes you will move them to another place. One way to ensure that TACT will always find these files is to put them in a directory listed in the DOS PATH. If TACT programs have no other way to find the files they need, they will first look in the current logged directory, and then in the various places specified on the DOS PATH.
If you wish, however, you can specify a list of one or more directories that TACT programs should search for files they need.
Do so by setting the TACTPATH environment variable:
This DOS command names a directory "\TACT" on the "C" drive, and stores that in the TACTPATH environment variable. This command tells any TACT program to look for its files in "C:\TACT".
If the TACTPATH environment variable is specified, TACT will not use the DOS PATH to look for files. Whether TACTPATH is set or not, however, TACT will always look first in the current directory.