Windows Vista 7 Beta: Face Plants Instantly!

I tried Windows 7 Beta for the first time today. I set up a VirtualBox OSE virtual machine with a 20GB hard disc, 3GB of RAM and 128MB of video memory. My host system is a Dell 720 with an Intel Core 2 Quad 2.66GHz CPU, 8GB of RAM, 2xNVIDIA 7900 graphics cards in SLI and 1.5TB of hard drive space running Ubuntu 8.10 64-bit version.
I doubt I should be having problems installing this Windows 7 in a virtual machine. But I do. It face plants instantly. The installer iso loads and then tells me to insert the installation disc. Clearly I'm missing something here. Here's a screenshot.

Then of course there's the whole download process. Why was all the registering necessary? It's an open beta supposedly free for anybody to test until the 1st of August 2009.

It probably goes without saying I'm not impressed. Ubuntu 64-bit runs fine in a virtual machine. I don't see why Windows shouldn't. Clearly I need to go back and look at the instructions again. But this is poor form from Microsoft. The stupid thing won't even install. Is this really beta software?