Check for .NET during InitializeSetup

[CustomMessages]
dotNETnotpresent=Foi detectado que seu computador não possui o .NET Framework 4.0. Para que o aplicativo execute normalmente é necessário tê-lo instalado. %n%nDeseja instalar?

[Code]
function InitializeSetup(): Boolean;
var
  Q: Integer;
begin
    Result := False;
    if not RegKeyExists(HKEY_LOCAL_MACHINE, 'SOFTWARE\Microsoft\.NETFramework\policy\v4.0') then begin
    //Registry entry was not found, quesion will appear
        Q := MsgBox(ExpandConstant('{cm:dotNETnotpresent}'), mbInformation, MB_YESNO);
        if Q = IDYES then begin
        //If the asnwer is YES, Setup will initialize
        //If the answer is NO, Setup will terminate
            Result := True;
        end;
    end
    else begin
    //Registry entry was found, Setup will initialize
        Result := True;
    end;
end;