IE8 Automatic detect setting uncheck

Hi All,

I need your help to uncheck  the IE automatic detect settings via GPO, already i have configred my GPO, which i havent enabled the automatic detect settings. But still my users are not able to browse the intranet pages due to this setting enabled automatically in the IE8. Kindly help me how to fix this issue, as i have gone through so many forums, but i couldnt get a solid answer for this.