Windows XP Home refuses to connect to dialup

[Dan Lewis]

I work Tech Support for a dialup internet provider. We've been
experiencing technical difficulties regarding a good portion of our
Windows XP users. Whenever they attempt to connect, they get the
following error:

Error 691: Access was denied because the username and/or password was
invalid on the domain.

We've tried everything, including:

Uninstalling / reinstalling the modem
Changing the FIFO buffers to 1/1
Upgrading the Driver
Rolling Back the Driver
Changing both Speed and Port Speed to 19200

And other minor things such as disabling anti-virus, ICF, removing
Client for Microsoft Networks, etc...

Note: We also disabled the NIC as well, and it was able to connect
after that, but only once, and then it proceeded to fail again...

Modem in this case: Intel 537EP V9x DF PCI Modem
Windows XP Home

What else can we try besides this?

 

[Guest]

Read as follows, hope it helps for you:

DUNS Error 691
http://www.modemsite.com/56k/duns691.asp

310431 - "Error 691" or "Error 734" When You Attempt to Establish a Dial-Up
Connection
http://support.microsoft.com/defaul...port/kb/articles/q310/4/31.asp&NoWebContent=1