Hi, I formatted and installed the 4.0RC2 beta and saw that I needed a new reg key, but when it tried to create one I received an "Unknown error"

I'm using Windows 7 x64.
Screenshot:
http://cl.ly/b6de7cbcdddc43e531e3
I also didn't see an option in the setup process to specify the options dir... I save my settongs on an external HD. Is it still possible to configure this setting?
Thanks!