This policy setting specifies whether when there is a problem connecting with an Internet server to provide a detailed description with hints about how to correct the problem. If you clear this check box the user sees only the error code and the name of the error.If you enable this policy setting when there is a problem connecting with an Internet server the user does not see a detailed description or hints about how to correct the problem. The user cannot change this policy setting.If you disable this policy setting when there is a problem connecting with an Internet server the user sees a detailed description with hints about how to correct the problem. The user cannot change this policy setting.If you do not configure this policy setting the user can turn on or turn off details in these error messages.
Windows Components\Internet Explorer\Internet Settings\Advanced settings\Browsing
User
At least Internet Explorer 7.0
HKCU\Software\Policies\Microsoft\Internet Explorer\Main!Friendly http errors
inetres.admx