>>But you still haven't said what the exact same error is !
>
>I said it a couple of times. The Setup thinks that I don't have .NET 4.0 and VS Shell 2010 installed. Trying to install from the CD always fails with the exact same message.
>>
>>>It wants to get vs_setup.msi for VS 2010 Ultimate and I have no idea where to get it.
>>
>>MSDN downloads presumably?
>>
>
>The question is - how will I get to the right download and how can I download it after my MSDN subscription has already expired.
>
>>Never tried this but it might help : http://msdn.microsoft.com/en-us/library/ms144256.aspx
>
>I'm not upgrading my existing SQL Server 2008 R2, I want to install SQL Server 2012 as a new instance and switch between them at will.

Is your SQL2012 the eval edition or a licensed edition? If your MSDN has expired, I'm assuming it is the eval?

If not and this is a version you paid outright for, I'd make a product support call to Microsoft and have them figure out what is wrong with their installer. Being their problem (which I'm confident it is) they should waive any fee for the support.

Reading this thread and the msdn thread it's pretty obvious this is another screwed installer that Microsoft has rushed out the door. You're being used as a beta tester at this point.