Issue:
"One of my clients loaded Office 2007 and tried to set up outlook. He put in an Exchange server name which doesn't exist. Now when we start outlook it looks for the server and when it doesn't find it outlook closes down. How do I stop it looking for the exchange server and get it to use a pop3 account."

Solution:
Control Panel->Mail Icon->Accounts. Install your POP3 or IMAP account and remove the Exchange account.