-- in class definition
[DllImport("KERNEL32.DLL", EntryPoint = "SetProcessWorkingSetSize", SetLastError = true, CallingConvention = CallingConvention.StdCall)]
internal static extern bool SetProcessWorkingSetSize(IntPtr pProcess, int dwMinimumWorkingSetSize, int dwMaximumWorkingSetSize);
[DllImport("KERNEL32.DLL", EntryPoint = "GetCurrentProcess", SetLastError = true, CallingConvention = CallingConvention.StdCall)]
internal static extern IntPtr GetCurrentProcess();
-- code to call when you want to reduce the memory
IntPtr pHandle = GetCurrentProcess();
SetProcessWorkingSetSize(pHandle, -1, -1);