How to Setup the Office Communicator 2007 Client
After installing open up the software and click the down arrow on the menu bar.
Click Tools and then Options.
In the Sign-in address: section enter your username@klz.org.uk and click Advance.
Ensure Automatic configuration is selected.
Click OK twice and then click sign in.
Enter your user name and password and click Sign In
Tip: a new hotfix: http://www.microsoft.com/downloads/details.aspx?FamilyID=1ad57f8f-78f7-45f6-a8c0-805936f46645&displaylang=en