I've been trying for the past 3 hours to get the Pre-RC1 of Vista to install.
I first tried to upgrade my Vista Beta 2 installation by booting the the DVD
(like you would with XP) but was informed that I would actually have to
launch the installer from within Beta 2 to do so. So I exited, logged into
Beta 2, and upon my attempt to upgrade, I received the following error:

"Windows cannot install the required files. The file may be corrupt or
missing. Make sure all files for installation are available, and restart the
installation. Error code: 0x80070017"

I thought maybe there was a problem upgrading, so I attempted a custom
installation to the Beta 2 partition from the installer launched from withing
Beta 2, as well as by booting to the DVD, and launching from my XP SP2
Partition, and received the same error each time. I burned the DVD as slowly
as my burner would support, to make sure this type of error did not occur...

Does anyone have any thoughts?