Add/remove not showing the programs list

hi everybody…Recently when i tried to uninstall a software from add/remove i found that the name of that software had been moved from there even though i am using that software…Moreover there was no uninstall tab when i selected a program(in the depleted list…no ms office…no windows in the list) to uninstall…it just showed me the details of that program and the amount of space occupied by it…Can anybody please help me in solving this weird problem??