virtualbox.org

I have VB 4.3.20 r96997 running on a Windows 8.1 host. The host is a gaming laptop (Asus G75V) with 32GB ram.

I currently have Windows Server 2012 R2 x64 running as a guest. I downloaded the new windows server preview iso (en_windows_server_technical_preview_x64_dvd_5554304.iso) to do an upgrade. I double-checked the ISO by computing its hash (SHA1) after download and comparing it to the published hash on MSDN. The hashes match, so I'm reasonably certain that the ISO bits are valid.

The setup program launched, copied some files, and then rebooted the VM. When it came back up it booted into the setup bootstrapper (as expected) and attempted to continue the install as is typical. However, at some point during the "install features and settings" step, it bails, does a rollback, and reboots back into 2012 R2. When I logged in as the administrator, I was presented with the following prompt:



I checked the event logs and didn't find anything useful there. Latest VBox.log pasted at the bottom.
My settings are as follows:



Does anyone have any idea why this might be failing?

My VBox.log is attached in compressed form, or can be viewed here: http://pastebin.com/FU9WAiQB

You should compress a vbox.log file and then attach it.

Right. Duh

It's attached to the OP.