Do you have any external Devices connected to the system? Removing whatever you can could help.
Can you get the system up long enough to get to the Recovery options and boot into SAFE Mode?
Since it might be a video driver situation, booting with a basic video presentation might help you stabilize long enough to do some trouble shooting. Is the 10 GB of memory an OEM install or did you change it?
You don't say which preview build you are running. I suppose you don't currently have the ability to update, even with an .iso file..
If you want to go back to 8.1, does you OEM have a built in way to do that, such a special key during boot or something like holding the power button during start?