' Prüft, ob eine EXE-Datei bereits ausgeführt wird und gibt im Erfolgsfall 
' entweder
' das Fensterhandle oder die Process-ID zurück
Public Function IsEXERunning(ByVal sFilename As String, _
  Optional ByVal iReturn As procReturnValue = ProcessID) As Long
    Dim nResult As Long
 
  ' Je nach System...
  If IsWinNT() Then
    ' NT4 - Sonderbehandlung :-)
    Dim lCb As Long
    Dim lCbNeeded As Long
    Dim lCbNeeded2 As Long
    Dim lProcID() As Long
    Dim lModules(1 To 200) As Long
    Dim hProcess As Long
    Dim sModuleName As String
    Dim n As Long
 
    ' alle laufenden Prozesse ermitteln
    lCb = 8: lCbNeeded = 96
    Do While lCb <= lCbNeeded
       lCb = lCb * 2
       ReDim lProcID(lCb / 4) As Long
       EnumProcesses lProcID(1), lCb, lCbNeeded
    Loop
 
    For n = 1 To lCbNeeded / 4
       ' Prozess-Handle ermitteln
       hProcess = OpenProcess(PROCESS_QUERY_INFORMATION _
          Or PROCESS_VM_READ, 0, lProcID(n))
       If hProcess <> 0 Then
         nResult = EnumProcessModules(hProcess, _
           lModules(1), 200, lCbNeeded2)
           If nResult <> 0 Then
             sModuleName = Space(MAX_PATH)
             nResult = GetModuleFileNameEx(hProcess, _
               lModules(1), sModuleName, Len(sModuleName))
             sModuleName = LCase$(Left$(sModuleName, nResult))
 
             ' sModuleName beinhaltet den kompletten Pfad!
             If Right$(sModuleName, Len(sFilename) + 1) = _
               "\" + LCase$(sFilename) Then
               ' Jepp - EXE gefunden!
               If iReturn = Handle Then
                 IsEXERunning = ProcID2hWnd(lProcID(n))
               Else
                 IsEXERunning = lProcID(n)
               End If
               Exit For
             End If
           End If
       End If
       CloseHandle hProcess
    Next n
 
  Else
    ' bei allen anderen Systemen...
    Dim lSnapshot As Long
    Dim uProcess As PROCESSENTRY32
 
    ' "Snapshot" des aktuellen Prozess ermitteln
    lSnapshot = CreateToolhelpSnapshot(TH32CS_SNAPPROCESS, 0&)
    If lSnapshot <> 0 Then
      uProcess.dwSize = Len(uProcess)
 
      ' Ersten Prozess ermitteln
      nResult = ProcessFirst(lSnapshot, uProcess)
 
      Do Until nResult = 0
        ' Prozessliste durchlaufen
        If InStr(LCase$(uProcess.szexeFile), sFilename) > 0 Then
          MsgBox "EXE gefunden"
          If iReturn = Handle Then
            IsEXERunning = ProcID2hWnd(uProcess.th32ProcessID)
          Else
            IsEXERunning = uProcess.th32ProcessID
          End If
          Exit Do
        End If
 
        ' nächster Prozess
        nResult = ProcessNext(lSnapshot, uProcess)
      Loop
 
      ' Handle schliessen
      CloseHandle lSnapshot
    End If
  End If
End Function