start /low %SystemRoot%\system32\notepad.exe

Option Explicit

Private Declare Function SetPriorityClass Lib "kernel32" (ByVal hProcess As Long, ByVal dwPriorityClass As Long) As Long
Private Declare Function GetCurrentProcessId Lib "kernel32.dll" () As Long
Private Declare Function OpenProcess Lib "kernel32" (ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, ByVal dwProcessId As Long) As Long

 '/* -- флаги приоритетов для процессов -- */ 
Private Const NORMAL_PRIORITY_CLASS   As Long = &H20     ' средний 
Private Const IDLE_PRIORITY_CLASS     As Long = &H40     ' низкий 
Private Const HIGH_PRIORITY_CLASS     As Long = &H80     ' высокий 
Private Const REALTIME_PRIORITY_CLASS As Long = &H100    ' реального времени 

Private Const PROCESS_SET_INFORMATION As Long = &H200



Private Sub Form_Load()
     'Call SetPriorityClass(ByVal OpenProcess(ByVal PROCESS_SET_INFORMATION, ByVal 0&, GetCurrentProcessId), ByVal IDLE_PRIORITY_CLASS) 
    Call SetPriorityClass(ByVal OpenProcess(ByVal PROCESS_SET_INFORMATION, ByVal  0 &, GetCurrentProcessId), ByVal HIGH_PRIORITY_CLASS)
End Sub