If you have an old copy of internet newsgroups hanging around in your public folders from an old server here are the steps to get rid of it.
Before making any system change it is important that you have a backup of your computer. This post is provided “AS IS” with no warranties and confers no rights, before following any steps on this site you must take responsibility for your own actions.
Install support tools for exchange server 2007 on the server
Open up ADSI Edit
Click Action
Click Connect to…
In the dialog box under “Select a well known naming context” Select Configuration
Click OK.
Open Configuration
Open CN=Services
Open CN=Microsoft Exchange
Open CN=”your domain name”
Open CN=Administrative Groups
Open CN=Exchange Administrative Group
Open CN=Servers
Open CN=”your server name”
Open CN=Information Store
Remove the folder containing your public folders
Open outlook and manually select send and receive
The Internet Newsgroups folder either should disappear if it still exists then it may be a synchronized copy from another folder.