The screen is black with the following text in white:
Your PC needs to restart.
Please hold down the power button.
Error Code: 0x0000005D
Installing the consumer preview had no problems.
If I boot into Windows 8 (Consumer Preview) and run the Release Preview setup from the DVD manually, I get the "Your CPU is not compatible" error message. My machine does meet the requirements as far as I know: P4 2.6 GHz, 1.75 GB of RAM.