Как получить / установить приоритет процесса в Win9x/Me

Const
    ppIdle                  : Integer = -1;
    ppNormal                : Integer =  0;
    ppHigh                  : Integer =  1;
    ppRealTime              : Integer =  2;

Function SetProcessPriority( Priority : Integer ) : Integer;
Var
    H : THandle;
Begin
    Result := ppNormal;
    H := GetCurrentProcess();
    If ( Priority = ppIdle ) Then
        SetPriorityClass( H, IDLE_PRIORITY_CLASS )
    Else If ( Priority = ppNormal ) Then
        SetPriorityClass( H, NORMAL_PRIORITY_CLASS )
    Else If ( Priority = ppHigh ) Then
        SetPriorityClass( H, HIGH_PRIORITY_CLASS )
    Else If ( Priority = ppRealTime ) Then
        SetPriorityClass( H, REALTIME_PRIORITY_CLASS );
    Case GetPriorityClass( H ) Of
        IDLE_PRIORITY_CLASS     : Result := ppIdle;
        NORMAL_PRIORITY_CLASS   : Result := ppNormal;
        HIGH_PRIORITY_CLASS     : Result := ppHigh;
        REALTIME_PRIORITY_CLASS : Result := ppRealTime;
    End;
End;

Function GetProcessPriority : Integer;
Var
    H : THandle;
Begin
    Result := ppNormal;
    H := GetCurrentProcess();
    Case GetPriorityClass( H ) Of
        IDLE_PRIORITY_CLASS     : Result := ppIdle;
        NORMAL_PRIORITY_CLASS   : Result := ppNormal;
        HIGH_PRIORITY_CLASS     : Result := ppHigh;
        REALTIME_PRIORITY_CLASS : Result := ppRealTime;
    End;
End;

Как использовать:
    Function SetProcessPriority( Priority : Integer ) : Integer;

для установки приоритета Вашего приложения, либо:

    Function GetProcessPriority : Integer;

для получения приоритета.