Delphi 通过WMI读取系统信息问题

[cate1019]

function GetWMIProperty(WMIType, WMIProperty: string): string;
var Wmi, Objs, Obj: OleVariant;
  C: Cardinal;
  i,Len:integer;
  tempItem:IEnumVariant;
begin
  Wmi:= CreateOleObject('WbemScripting.SWbemLocator');
  Objs := Wmi.ConnectServer('.','root\cimv2').ExecQuery('Select * from Win32_' + WMIType);
  tempItem:=IEnumVariant(IUnknown(Objs._NewEnum));
  Result:='';
  while (tempItem.Next(1, obj, c) = S_OK) do
  begin
    Obj := Obj.Properties_.Item(WMIProperty, 0).Value;
    if not VarIsNull(obj) then
    begin
      Result :=Result +trim(Obj);
      break;
    end;
  end;
end;

调用函数查询BIOS序列号

ShowMessage(GetWMIProperty('BIOS', 'SerialNumber'));

结果显示“RPC服务器不可用。",断点停留在

  Objs := Wmi.ConnectServer('.','root\cimv2').ExecQuery('Select * from Win32_' + WMIType);

这一行。
同样用微软的WMICodeCreator查询，就可以正常查询，是不是我哪里有错误？

[bwsoft1]

CoInitialize(nil);先调用他