>>One way out of this would be to use an external modem, which can be reset independently from the machine itself. Another thing would be to add an "EXIT" after the last line of the batch file, so it would at least close the DOS window when done. Though, I don't know whether that would help.
>>
>I put an Exit in the line in the .bat file. Yet no luck.

That means it wasn't done, i.e. it never arrived at that line. Your PCAW is getting stuck - it tries to reset the modem, waits for response, nothing happens, tries again, while .t.