利用Api函數計算Windows從啟動后所運行的總時間 

Private Declare Function GetTickCount Lib "kernel32" () As Long

Private Sub Timer1_Timer()
Dim hour As Integer
Dim minute As Integer
Dim second As Integer
hour = GetTickCount \ 1000 \ 60 \ 60
Label1.Caption = Str(hour) + "小時"

minute = (GetTickCount - hour * 60 * 60 * 1000) \ 1000 \ 60
Label2.Caption = Str(minute) + "分鐘"

second = (GetTickCount - Val(Label1.Caption) * 60 * 60 * 1000 - Val(Label2.Caption) * 60 * 1000) \ 1000
Label3.Caption = Str(second) + "秒鐘"
End Sub