Program Manager
Program Manager is the shell of Windows 3 . x and Windows NT 3 . x operating systems . 
<triplet> Program Manager <subj> shell <obj> instance of <subj> Windows 3.x <obj> operating system <triplet> shell <subj> operating system <obj> facet of <triplet> Windows 3.x <subj> operating system <obj> instance of <triplet> Windows NT <subj> operating system <obj> instance of