Error 718: PPP timeout

After reinstalling Windows NT 4.0 Server because of a crashed harddisk, I can not connect to the internet. I get an error message: 718 timeout waiting for PPP.
I searched the MS Knowlegde base and tried their preposed solutions and I’ve tried 3 different modems.
I also have another NT 4.0 Server and that one works just fine. I checked the settings and they are the same. Still I can’t find a solution for this
Can anyone shed some light on this matter??
Thanx
William