使用WriteFile() GetLastError()的返回值是5，如何提升权限？谢谢

ComHandle=CreateFile(Port,

		GENERIC_READ||GENERIC_WRITE,

		0,NULL,OPEN_EXISTING,NULL,NULL);

	if(ComHandle==INVALID_HANDLE_VALUE){MessageBox("1"); return 0;}

	char tmpP[11]="9600,n,8,1";//设置通讯参数

	DCB dcb;

	if(GetCommState(ComHandle,&dcb)==0){MessageBox("2");return -1;}

	if(BuildCommDCB(tmpP,&dcb)==0){MessageBox("3");return -1;}

	if(SetCommState(ComHandle,&dcb)==0){MessageBox("4");return -1;}

	COMMTIMEOUTS TimeOuts;//设置超时时间

	GetCommTimeouts(ComHandle,&TimeOuts);

	TimeOuts.ReadIntervalTimeout=2000;

	TimeOuts.ReadTotalTimeoutConstant=400;

	TimeOuts.ReadTotalTimeoutMultiplier=400;

	TimeOuts.WriteTotalTimeoutMultiplier=40;

	TimeOuts.WriteTotalTimeoutConstant=400;

	if(SetCommTimeouts(ComHandle,&TimeOuts)==0){MessageBox("6");return -2;}

	if(SetupComm(ComHandle,2048,1024)==0){MessageBox("7");return -3;}//设置缓冲区

	//PurgeComm(ComHandle,PURGE_RXABORT||PURGE_RXCLEAR);

	//PurgeComm(ComHandle,PURGE_TXABORT||PURGE_TXCLEAR);

	if(ComHandle<0){MessageBox("111");return 111;}

 	BYTE m_SendBuffer[1];	

	DWORD m_Number;

 	m_SendBuffer[0]=0x06;

 	if(WriteFile(ComHandle, m_SendBuffer, 1 , &m_Number,NULL)==0)

	{

		DWORD ErrorCode;

		ErrorCode=GetLastError();

		char temp[5];

		sprintf(temp,"%d",ErrorCode);

		MessageBox(temp);

		MessageBox("here!");

		return -5;

	}

	CloseHandle(ComHandle);

//	Write();

	MessageBox(Port);

	return 0;