Outlook 2003 on Vista Ultimate cannot connect to Exchange 5.5

Hi there,

I have recently installed Windows Vista Ultimate on my Acer Laptop, with Centrino 1.6, and 1.25GB RAM. Everything works fine, however, when I try to connect to my Exchange Server (5.5), it opens the window for me to enter my domain username and password, and simply WILL NOT authenticate me! I cannot add my laptop to the domain as well (Windows NT4).

I do know that Outlook 2007 will not work with Exchange 5.5, but Outlook 2003 on Vista? Everything worked fine when I had XP Pro installed for almost 2 years.

Can you please help me?! I have not been able to check my mail for almost a week!

Thanks and best regards,

Shiv