Why can I only change/remove only some of my programs?

When I click onto some of my programs in the control panel - on remove or change - nothing happens. Only the most recent programs I can remove - ones that I've had over the last 6 mos. or so.Why can I only change/remove only some of my programs?Its bugged out. Try run CCleaner - http://www.ccleaner.comWhy can I only change/remove only some of my programs?I assume your os is Windows.Try going into Safe mode than remove your unwanted programs.