delphi2006获取记录集的大小的函数是什么啊？

[ju1]

var
OSVersionInfo: TOSVersionInfo;
begin
Result:= -1;
// ZeroMemory(@OSVersionInfo,SizeOf(OSVersionInfo));
OSVersionInfo.dwOSVersionInfoSize := sizeof(OSVersionInfo);
GetVersionEx(OSVersionInfo);
if OSVersionInfo.dwPlatformId = VER_PLATFORM_WIN32_NT then
begin//1
if (OSVersionInfo.dwMajorVersion = 4) and
(OSVersionInfo.dwMinorVersion = 0) then
Result:=1000;
if (OSVersionInfo.dwMajorVersion = 5) and
(OSVersionInfo.dwMinorVersion = 0) then
Result:=2000;
if (OSVersionInfo.dwMajorVersion = 5) and
(OSVersionInfo.dwMinorVersion = 1) then
Result:=2001;
if (OSVersionInfo.dwMajorVersion = 5) and
(OSVersionInfo.dwMinorVersion = 2) then
Result:=2003;
end;//1
if OSVersionInfo.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS then
begin//2
Result:=98;
end;//2
end;



在delphi7中OSVersionInfo.dwOSVersionInfoSize 是148 可以正常得到版本好
但delphi2006中OSVersionInfo.dwOSVersionInfoSize只有24 无法正常获得版本号
哦OSVersionInfo.dwPlatformId始终是0
这是为什么？