Private Declare Function QueryPerformanceFrequency Lib "kernel32" (lpFrequency _
  As Currency) As Long
Private Declare Function QueryPerformanceCounter Lib "kernel32" ( _
lpPerformanceCount As Currency) As Long
Private tStart As Currency, tEnd As Currency, tFreq As Currency, tScale As _
Double, Runtime As Double

    QueryPerformanceFrequency tFreq
    tScale = 1 / tFreq 'ergibt bei Multiplikation die Zeit in Millisekunden

    Runtime = 0
    QueryPerformanceCounter tStart
    Do While Runtime < 300#
        QueryPerformanceCounter tEnd
        Runtime = (tEnd - tStart) * tScale
    Loop