Can't use dialup after changing settings

I have recently had a broadband connection, I installed
the drivers and change the computer settings (IP, DNS,
Gateway, .) and I have realized that my DSL line is not
active yet by the local carrier.
I went back to use my dial up connection, but it is not
longer working.
I am having below problems

I restarted my computer several times, but it is taking
too long before it prompts me for the windows' login user
name & password. It takes about 3-4 min on "preparing
network connections..."
I use a VPN access, and my dialup is no longer working. I
no longer get to the stage where it prompts me for my
user name and passcode. I am receiving the following
error message "Error 619: The specified port is not
connected"
Detail:
"This is an rare error, but it is usually simple
First, restart your computer to make sure that any recent
configuration changes have taken place.
If restarting your computer doesn't solve the problem,
then:
Check your dial up networking configuration.
Verify that your dial up adapter is configured to use the
necessary TCP/IP protocol."

I also have a non VPN access where I use an ISP for a
dialup, but I can no longer acess any web site.
I am not sure what cause the problem, but I didn't have
this issue before changing the Brodband settings. Could
you please help