Access to this feature has been disabled by a restriction set by your system administrator (Internet Explorer)

This message appear while my customer want to upgrade their license OnGuard 2013, we try upgrade with Internet Explorer 8.0. if i check in Internet Option - Security, i cannot modify in this setting. in this menu tab appear message "Some settings are managed by your system administrator". So i try searching how to fix this problem. Just few times, i found many tutorial how to fix it. Here we go:
- The Security Center can only be disabled on PCs connected to an Active Directory Domain, so that one must be, or is infected with malware.
- That policy, and hiding the Internet Tools Security tab, can be set via a domain policy, or on each individual PC using gpedit.msc.

How to Fix:
- Open  gpedit.msc (from run)
- Find Computer Configuration or User Configuration\Administrative Templates\Internet Explorer\Internet Control Panel
- check in Security Zones then setting Not Configured if any enabled setting.

Hope this help you..