>>>OK I dowloaded SQL Server 2008 r2 Developer
>>>
>>>I started the install
>>>and I get an error:
>>>[Error Message]
>>>The credentials you provided for the SQL Server Agent service are invalid. To continue, provide a valid account and password for the SQL Server Agent service.
>>>
>>>[Details]
>>>Microsoft.SqlServer.Configuration.Agent.InputValidationException: The credentials you provided for the SQL Server Agent service are invalid. To continue, provide a valid account and password for the SQL Server Agent service.
>>>================================================================================
>>
>>It should give you the option to use existing Service accounts (a dropdown list). Pick one of them - they do not need a password.
>
>unfortunately not. see attachment
>
>i typed in 'cortielp' (my login to my computer) but it doesn't like it
>
>Peter

Select "Use the same account for all services" button once you have selected a service account.