>I set up the At command on my Win NT. It work for 3 days and after it did not work any more. It there a setting in Win NT for this?

Have you setted it from the DOS prompt? If yes, can you provide the command line.

I did it once, and after I found all the problems I had from the command line, I switched to the user interface where many bugs were not found as they were from the DOS prompt.