First install the 2007 Office system Administrative Template files (ADM, ADMX, ADML) and Office Customization Tool version 2.0 if you haven’t already done so.
In Group Policy Editor navigate to User Configuration -> Polices -> Administrative Templates -> Microsoft Office Outlook 2007 -> Tools | Account Settings -> RSS Feeds
-Default RSS Feeds -> Set to Disabled
-Synchronize Outlook RSS Feeds with Common Feed List -> Set to Disabled
-Turn off RSS Feature -> Enabled
After all these are set you can reboot the workstations or force a GPO update by using gpupdate /force
By disabling RSS feeds you are cleaning up space on your Exchange store and speeding up your users outlook. I recommend doing this in any business.