Hello, this is C# version of the code: [DllImport( "powrprof.dll", EntryPoint="SetSuspendState", CharSet=CharSet.Ansi)] private static extern int SetSuspendState(int Hibernate, int ForceCritical, int DisableWakeEvent); you should call it like this: SetSuspendState(1,0,0); I found this information here Maqsood Ahmed - MCAD.net Kolachi Advanced Technologies http://www.kolachi.net