the administrator has set policies to prevent this installation with WINDOWS 8

I am currently trying to delete some programs like Itunes or Oovoo but everytime I try, the message ''the administrator has set policies to prevent this installation'' appears and than it say ''you do not have sufficient access to uninstall please contact your administrator'' I DON'T KNOW WHAT TO DO. 

I'm also having issues with the program conduit search I can't uninstall it! 

Help me please