Running threads count

you can use the CreateToolhelp32Snapshot function with the TH32CS_SNAPTHREAD flag

see this code.

  uses
  PsAPI,
  TlHelp32,
  Windows,
  SysUtils;

    function GetTThreadsCount(PID:Cardinal): Integer;
    var
        SnapProcHandle: THandle;
        NextProc      : Boolean;
        TThreadEntry  : TThreadEntry32;
        Proceed       : Boolean;
    begin
        Result:=0;
        SnapProcHandle := CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0); //Takes a snapshot of the all threads
        Proceed := (SnapProcHandle <> INVALID_HANDLE_VALUE);
        if Proceed then
          try
            TThreadEntry.dwSize := SizeOf(TThreadEntry);
            NextProc := Thread32First(SnapProcHandle, TThreadEntry);//get the first Thread
            while NextProc do
            begin
              if TThreadEntry.th32OwnerProcessID = PID then //Check the owner Pid against the PID requested
              Inc(Result);
              NextProc := Thread32Next(SnapProcHandle, TThreadEntry);//get the Next Thread
            end;
          finally
            CloseHandle(SnapProcHandle);//Close the Handle
          end;
    end;

And call in this way, using the GetCurrentProcessId function wich Retrieves the PID (process identifier) of your application.

Var
Num :integer;
begin
 Num:=GetTThreadsCount(GetCurrentProcessId);
end;