PPP Error 720/721 on dial-up

Hi,

Scenario:
Arrived at work Monday morning, Windows2000 server with service pack 2 not starting.

We eventally decided to
1) Fresh install
2) Restore from full system backup taken Friday evening (including system state) using built-in MS-Backup.

Problem:
Everything back to normal except that when we try to dial out using an ISDN or analogue modem we receive error message 720 or 721 “PPP not configured correctly etc”. after the dial-up is verifying username/password.

We have uninstalled, rebooted and reinstalled TCP/IP, installed modems from scratch and created new dial-up settings – all with the same result.

Any help would be appreciated.

Regards,

Mario