Changing IM default message

I need some help changing the default message in Microsoft Instant Messenger 5.1
I have searched all over the internet and tried to find any resource on changing the warning that pops up at the top of instant messenger when using Microsoft Office Live Communications Server 2005.

we want to change the message that says “Never give out your password or credit card number in an instant message conversation.” to something along the lines off never discuss private patient information while using IM.