Broadband internet connection

I have windows XP. In connecting to the internet I have selected "Save
username and password". The result is I can elect to connect automatically -
for all users of this machine or anyone on the network. On another partition
I have installed Windows Vista RC1. In trying to connect to the internet via
a broad band connection I get a security error (UID and Password). I go back
to XP, disable auto connection on my default connection and setup a new
connection with the same UID and password - again it fails because of UID and
Password violation. So it seems I can only connect via my original connection
setup. (I am going to contact my ISP to verify my password. --- I cut an
pasted the ID to make sure it is correct.)

But this brings up my question. Where is the User Name and Password stored
for the Broadband connection?

Thanks
Johnnie