I was busily preparing my new VMs all night (shiny new VMs!!). Planning to get 2 Windows 2008 R2 Enterprise boxes out as my new playgrounds, one as a Domain Controller, another one as my new Denali CTP3 box.

When I was starting to install Denali, not long after launching the install, I got this weird issue just as I was clicking next on the Product Key window:

SQL Server Setup has encountered the following error:
The handle is invalid. (Exception from HRESULT: 0×0070006 (E_HANDLE))

At first I was thinking maybe my ISO was corrupt, or my VM was wonky! Good thing I stumbled across this old connect post about sql2k8 rtm (dev x64) failed install. Quoting the last answer:

This is a MSDN version so the product key is pidded but it is not enabled as read-only. So, when you’re presented with the product key dialog, you can muck it up.

To reproduce, simply select the “Specify a free edition” radio button without changing the shown PID, then reselect the “Enter the product key” radio button (again without changing the PID) and continue with the installation.

So to recap, the solution is to select the “Enter the Product Key” choice (yup, even if it’s blank). That’s all it took, worked like magic.