You can easily enumerate processes in most OSs by using the well known toolhelp functions. Unfortunately the toolhelp functions don't work in NT4. So here's a function which enumerates processes and works well in all OSs.

type   TDAProcess = array of record     id      : dword;    // process id     exeFile : string;   // exe file (9x = full path; nt = name only)     session : dword;    // session id     sid     : string;   // user sid   end; function EnumProcesses : TDAProcess; // Example: function GetProcessSessionId(processId: dword) : dword; var i1 : integer;     pl : TDAProcess; begin   result := 0;   pl := EnumProcesses;   for i1 := 0 to high(pl) do     if pl[i1].id = processId then begin       result := pl[i1].session;       break;     end; end;