I use Vista Business, but I assume basic network portion would be the same.
Are you able to log on to the network with your Vista PC at all? Or, you are
logging in locally, then trying to run Outlook?
My first issue was not being able to login to our NT4 domain. Fortunately,
I attended Microsoft event one day, and got an e-mail address for Vista
project person. He told me to do this.
Start, All Programs, Administrative Tools, Local Security Policy, Local
Policies, Security Options, Network Security, select "Lan Manager
authentication level", change it to "Send LM & NTLM - use NTLMv2 session
security if negotiated".
Hope this will help you.
Since there are some apps which do not run on Vista, I run Virtual PC 2007,
and run Windows 2000 and Windows XP SP2 over it. Unfortunately, I cannot do
everything with Vista at this moment. As long as you are running equal or
older version of Windows on Virtual PC, you don't have to pay for the
licenses.