How to stop rograms running at startup

No matter what user logs on to this pc, Windows NT Explorer starts automatically during the logon. OS is NT 4.0 There is nothing in any profile startup group on the pc for NT Explorer, also ther is nothing in any login scripts. I have also checkedthe RUN and LOAD values in the regestry under HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows. Both have nothing in the string value.

Looking for sugestions. Thanks