Confusing on signing in with Messenger and MSN Messenger

I have 2 PCs connected with wired Ethernet and sharing a dialup 56k
connection thru ICS. PC1 (ICS PC) is running XP Professional while PC2 is
running XP Home. Office XP in installed on PC1 while PC2 is running Office
2000. I use Outlook for email.

I use a POP3 account for email from my local ISP. Currently I have the
version of Messenger installed with Windows XP SP2 installed. I have not
signed in with messenger yet and I am going to setup a new hotmail account.

Do I use my POP3 email account to setup my passport first and then setup my
hotmail account and load MSN Messenger 6? Will my POP3 work as a Passport?
I believe I read somewhere that unless the email address was an MSN email
address or hotmail account it would not work as a Passport? My email
account has a .net extension.

I have tried this on previous Windows installs and always seem to have
trouble signing in to Passport no matter what I do?

When I registered my copies of XP I used my ISP email address. This is why
I was wondering if I should go ahead and try signing in with this as a
Passport first, before setting up my hotmail account?

Any help here would really be appreciated. I have reloaded XP a number of
times trying to get Passport to work properly.

Also, since I have multiple users on both PC's do I select the option not to
save my passport information when I log in? The users all have their own
profiles setup.