Узнаём установленную версию ADO

function GetADOVersion: Double;
var 
 ADO: OLEVariant; 
begin 
 try 
 ADO := CreateOLEObject('adodb.connection'); 
 Result := StrToFloat(ADO.Version); 
 ADO := Null; 
 except 
 Result := 0.0; 
 end; 
end; 

// To use this function try something like: 
procedure TForm1.Button1Click(Sender: TObject); 
const 
 ADOVersionNeeded = 2.5; 
begin 
 if GetADOVersion then 
 ShowMessage('Need to install MDAC version 2.7') 
 else 
 ShowMessage(Format('ADO Version %n, is OK', [GetADOVersion])); 
end;