/// suggested alternative (about 100 times faster)
public static class ProcessInfoUtil
{
	public static System.Diagnostics.Process GetParentProcess() { return ParentProcessId == 0 ? null : System.Diagnostics.Process.GetProcessById(ParentProcessId); }

	public static readonly int ParentProcessId = GetParentProcessId();

	private static int GetParentProcessId()
	{
		var pi = new PROCESS_BASIC_INFORMATION();
		int actual;
		if (0 == NativeMethods.NtQueryInformationProcess(new IntPtr(-1), 0/*processbasicInformation*/, ref pi, pi.Size, out actual))
		{
			return (int)pi.InheritedFromUniqueProcessId;
		}
		else 
		{
			return 0;
		}
	}

	[StructLayout(LayoutKind.Sequential, Pack = 1)]
	private struct PROCESS_BASIC_INFORMATION
	{
		public IntPtr ExitStatus;
		public IntPtr PebBaseAddress;
		public IntPtr AffinityMask;
		public IntPtr BasePriority;
		public UIntPtr UniqueProcessId;
		public IntPtr InheritedFromUniqueProcessId;

		public int Size { get { return Marshal.SizeOf(typeof(PROCESS_BASIC_INFORMATION));}}
	}

	static class NativeMethods
	{
	[DllImport("NtDll", SetLastError=true)]
	public static extern int NtQueryInformationProcess(IntPtr ProcessHandle, int processInformationClass, ref PROCESS_BASIC_INFORMATION ProcessInformation, int processInformationLength, out int returnLength);
	}
}

/// this is the current implementation
 string wmiQuery = String.Format(CultureInfo.CurrentCulture,
                                            "Select * From Win32_Process Where Handle='{0}'",
                                            current.Id);

            using (CimSession cimSession = CimSession.Create(null))
            {
                IEnumerable<CimInstance> processCollection =
                    cimSession.QueryInstances("root/cimv2", "WQL", wmiQuery);

                int parentPid =
                    processCollection.Select(
                        cimProcess =>
                        Convert.ToInt32(cimProcess.CimInstanceProperties["ParentProcessId"].Value,
                                        CultureInfo.CurrentCulture)).FirstOrDefault();

                if (parentPid == 0)
                    return null;
...