Issue with IE8 installation removing users rights to edit Site to Zone lists in Internet Explorer and users unable to edit the Security Levels on Zones.
Add these two lines to a login script to disable the automatic launch of IE Enhanced Security (IE8 turns it on even if it is not installed on the server):
WRITEVALUE ("HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zonemap", "IEHarden", "0", "REG_DWORD")
WRITEVALUE ("HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zonemap", "IEHardenIENoWarn", "0", "REG_DWORD")
Then if you need the users to be allowed to edit the security levels you need to change the following settings in the GPO's:
Computer Configuration-->Admin Templates--> Windows Components--> Internet Explorer --> Internet Control Panel--> Security Page:
Locked-Down **** Zone Template has to be set to DISABLED, where *** is the Zone template that the users need to be able to edit.
This is when #IE8 is installed on a Windows Server 2003 Terminal Server.
Reference: http://support.microsoft.com/kb/933991