//单位MB

function getDiskFree(Drive: String): Int64;

var  FreeBytes: Int64;  TotalBytes: Int64; begin   if GetDiskFreeSpaceEx(Pchar(Drive),FreeBytes, TotalBytes, nil) then   begin   RESULT := FreeBytes;   end   else   begin    RESULT := 0;   end;   RESULT:=RESULT shr 20; end;