Hey guys, I just got SP1 beta DIRECT FROM MICROSOFT VIA WINDOWS UPDATE!!! And I'll tell you how...
But first... I am not experiencing the shutdown problems or any other problems so far with this direct from Microsoft update.
If you are interested, it's still at your own risk, but at least you know for sure that it is the REAL SP1 beta and not something that has been hacked.
As I mentioned before there are two prerequisite files that need to be installed by windows update before it downloads and installs the SP1. They are KB937287 and KB938371. Since these were installed, I think that is why I am not having any trouble this time.
Just follow this very simple hack and windows will install those two files and SP1 beta. It required several reboots. It is possible that you might get a "Windows is up to date" when you tell it to check for updates (I only got this message once), but eventually you'll get everything downloaded and installed.
This worked on my 64-Ultimate system. It works for 32-bit or 64-bit.
http://itsvista.com/2007/10/how-to-hack-windows-update-to-download-vista-sp1-beta/