Outlook 2003 won't reslove to Exchange server

[Ian]

I installed Outlook 2003 (removed previous version), go
into Control Panel, Double click "Mail", go to Email
Accounts, click Next to "Add a new e-mail account", select
Exchange Server, supply CORRECT exchange server name,
supply VALID user name, click "Check Name" and I get an
error message:

"The action could not be completed. The opeation failed."

Tried unistalling Office XP, reinsatll office XP - now
Outlook 2002 won't work either?

Checked RPC binding order;
Cannot Uninstall TCP/IP - only uncheck box.

Now I wish I hadn't started.......any ideas
Thanks
(e-mail address removed)