Type O in reply to the question

Voulez-vous que votre autoexec.bat soit
adapté automatiquement (O/N) (Do you want that your autoexec.bat is
adapted automatically (Y/N))

, then quit the installation program and restart your computer, so that the modifications are taken in account.

If you type N, you must make the adaptation yourself under editor. It is necessary:

To add the line
call Rep\astex\astexini.bat
at the end of your file autoexec.bat. Rep must be replaced by the name of the directory where you installed the distribution. For example, if you installed it in c:\ast, do add:
call c:\ast\astex\astexini.bat
To add, to the variable PATH of your file autoexec.bat, the main directory of the executables of AsTEX. With the example above:
PATH=directories;c:\ast\astex
where directories designates the directories that are already present in your variable PATH.

With Windows NT 4.0, proceed as above, with autoexec.nt (\winnt\system32 directory) instead ofautoexec.bat.