Getting Access Denied error on WMI / DCOM

I need some help to deal with WIN32: Access is denied error. I am trying to run WMI Local queries. I am getting error when I run those queries. I tried to work by restoring the rootsec and setup sect. But nothing worked here. I think there some issue with permission. But I am aware that there is no modification done recently which might arise this problem.

Go to Component Services. There you can find computers. Click on My Computer and then simply click on DCOM Config. here you can set the permissions for DCOM severs. This is one of the best way to fix such permission type problems. If this does not work then try to restore the default by using security config.