Windows 8 will install fine into an Oracle VirtualBox VM, but once the drivers are installed via Guest Additions, you can stuck in the reboot loop with the various error codes. It can happen at random times during the OS boot process, leaving you with the fish and the Morris-dancing dots on a black screen.
I got into the same situation and here is what I did:
1. When Windows 8 stops with the fish and the dancing dots, hit Ctrl-Alt-Del for 3 or 4 times
2. This interrupts the system sufficient for it to identify that there is a problem, so you should get the message saying “Preparing Automatic Repair”
3. The message will change to “Diagnosing your PC” after a pause
4. You will then get the usual message about rolling back to a previous System Restore point and possibly losing some installed programs/drivers
5. You have to click on Accept at this point
6. Windows 8 then goes into “Attempting Repairs” and may take some time doing it
7. Eventually Windows 8 will re-start
8. After a normal restart, you will get the Crash Report Notification dialog.
9. If you attempt to re-install Guest Addtionas and other drivers, enable the “Safe Mode” first , re-install, then disable Safe Mode before the reboot. This is a different process to all previous versions of Windows.
Hopefully you can extract yourself from this particular mess for the remainder of the Beta programme. AJS