what is top size of memory-mapped file?

[ephemera]

Hi,guys...
I had sucessfully used memory-mapped file on small file many times...but yesterday when i used it on 729M file,it failed...the code is following...what should i do to corret the code...thx in advance.

HANDLE hFile = ::CreateFile (pFileName, GENERIC_READ,
                          FILE_SHARE_READ, NULL, OPEN_EXISTING, 
                          FILE_ATTRIBUTE_NORMAL, 0);
	if ( hFile == INVALID_HANDLE_VALUE ) {
		return FALSE;
	}
	
	DWORD dwSizeHi;
	m_dwFileSize = ::GetFileSize(hFile, &dwSizeHi);
	HANDLE hFileMapping = ::CreateFileMapping(hFile, NULL, PAGE_READONLY,0, 0, NULL);
	if ( hFileMapping == NULL ) {
		::CloseHandle(hFile);
		return FALSE;
	}

	m_p = (LPBYTE)::MapViewOfFile(hFileMapping, FILE_MAP_READ,
					0, 0, 0);
	::CloseHandle(hFile);
	::CloseHandle(hFileMapping);
	if ( m_p == NULL ) {
		DWORD dwError = GetLastError();
		return FALSE;
	}

pFileName was file name,
i mapped the 729M file...m_p == NULL was TRUE;then dwError was 8,it stand for no enough memory...BTW.My memory size was 256M; OS was Windows 2000 server.

Regards,
Ephemera